From 516f7e8299c309ed909259c90c23cb0ce6a8e4f7 Mon Sep 17 00:00:00 2001
From: Joas Schilling <nickvergessen@owncloud.com>
Date: Tue, 7 Jul 2015 17:30:26 +0200
Subject: [PATCH] Add unit tests and automatic quoting

---
 lib/private/appframework/db/db.php            |   4 +-
 lib/private/db/connection.php                 |   6 +-
 .../compositeexpression.php                   |   8 +-
 .../{ => querybuilder}/expressionbuilder.php  |  46 +-
 lib/private/db/querybuilder/literal.php       |  40 +
 lib/private/db/querybuilder/parameter.php     |  40 +
 .../db/{ => querybuilder}/querybuilder.php    | 276 +++--
 lib/private/db/querybuilder/queryfunction.php |  40 +
 lib/private/db/querybuilder/quotehelper.php   |  75 ++
 .../icompositeexpression.php                  |   2 +-
 .../{ => querybuilder}/iexpressionbuilder.php |   6 +-
 lib/public/db/querybuilder/iliteral.php       |  29 +
 lib/public/db/querybuilder/iparameter.php     |  29 +
 .../db/{ => querybuilder}/iquerybuilder.php   | 126 ++-
 lib/public/db/querybuilder/iqueryfunction.php |  29 +
 lib/public/idbconnection.php                  |   4 +-
 .../db/querybuilder/expressionbuildertest.php | 338 +++++++
 .../lib/db/querybuilder/querybuildertest.php  | 941 ++++++++++++++++++
 tests/lib/db/querybuilder/quotehelpertest.php | 141 +++
 tests/lib/share/share.php                     |  16 +-
 20 files changed, 2039 insertions(+), 157 deletions(-)
 rename lib/private/db/{ => querybuilder}/compositeexpression.php (92%)
 rename lib/private/db/{ => querybuilder}/expressionbuilder.php (84%)
 create mode 100644 lib/private/db/querybuilder/literal.php
 create mode 100644 lib/private/db/querybuilder/parameter.php
 rename lib/private/db/{ => querybuilder}/querybuilder.php (75%)
 create mode 100644 lib/private/db/querybuilder/queryfunction.php
 create mode 100644 lib/private/db/querybuilder/quotehelper.php
 rename lib/public/db/{ => querybuilder}/icompositeexpression.php (98%)
 rename lib/public/db/{ => querybuilder}/iexpressionbuilder.php (98%)
 create mode 100644 lib/public/db/querybuilder/iliteral.php
 create mode 100644 lib/public/db/querybuilder/iparameter.php
 rename lib/public/db/{ => querybuilder}/iquerybuilder.php (84%)
 create mode 100644 lib/public/db/querybuilder/iqueryfunction.php
 create mode 100644 tests/lib/db/querybuilder/expressionbuildertest.php
 create mode 100644 tests/lib/db/querybuilder/querybuildertest.php
 create mode 100644 tests/lib/db/querybuilder/quotehelpertest.php

diff --git a/lib/private/appframework/db/db.php b/lib/private/appframework/db/db.php
index 529962002a..6134d33b6c 100644
--- a/lib/private/appframework/db/db.php
+++ b/lib/private/appframework/db/db.php
@@ -48,7 +48,7 @@ class Db implements IDb {
 	/**
 	 * Gets the ExpressionBuilder for the connection.
 	 *
-	 * @return \OCP\DB\IExpressionBuilder
+	 * @return \OCP\DB\QueryBuilder\IExpressionBuilder
 	 */
 	public function getExpressionBuilder() {
 		return $this->connection->getExpressionBuilder();
@@ -57,7 +57,7 @@ class Db implements IDb {
 	/**
 	 * Gets the ExpressionBuilder for the connection.
 	 *
-	 * @return \OCP\DB\IQueryBuilder
+	 * @return \OCP\DB\QueryBuilder\IQueryBuilder
 	 */
 	public function getQueryBuilder() {
 		return $this->connection->getQueryBuilder();
diff --git a/lib/private/db/connection.php b/lib/private/db/connection.php
index 9bb54883bf..ae5d22bf4d 100644
--- a/lib/private/db/connection.php
+++ b/lib/private/db/connection.php
@@ -29,6 +29,8 @@ use Doctrine\DBAL\Driver;
 use Doctrine\DBAL\Configuration;
 use Doctrine\DBAL\Cache\QueryCacheProfile;
 use Doctrine\Common\EventManager;
+use OC\DB\QueryBuilder\ExpressionBuilder;
+use OC\DB\QueryBuilder\QueryBuilder;
 use OCP\IDBConnection;
 
 class Connection extends \Doctrine\DBAL\Connection implements IDBConnection {
@@ -54,7 +56,7 @@ class Connection extends \Doctrine\DBAL\Connection implements IDBConnection {
 	/**
 	 * Gets the ExpressionBuilder for the connection.
 	 *
-	 * @return \OCP\DB\IExpressionBuilder
+	 * @return \OCP\DB\QueryBuilder\IExpressionBuilder
 	 */
 	public function getExpressionBuilder() {
 		return new ExpressionBuilder($this);
@@ -63,7 +65,7 @@ class Connection extends \Doctrine\DBAL\Connection implements IDBConnection {
 	/**
 	 * Gets the QueryBuilder for the connection.
 	 *
-	 * @return \OCP\DB\IQueryBuilder
+	 * @return \OCP\DB\QueryBuilder\IQueryBuilder
 	 */
 	public function getQueryBuilder() {
 		return new QueryBuilder($this);
diff --git a/lib/private/db/compositeexpression.php b/lib/private/db/querybuilder/compositeexpression.php
similarity index 92%
rename from lib/private/db/compositeexpression.php
rename to lib/private/db/querybuilder/compositeexpression.php
index cc57c52436..523f397e23 100644
--- a/lib/private/db/compositeexpression.php
+++ b/lib/private/db/querybuilder/compositeexpression.php
@@ -19,9 +19,9 @@
  *
  */
 
-namespace OC\DB;
+namespace OC\DB\QueryBuilder;
 
-use OCP\DB\ICompositeExpression;
+use OCP\DB\QueryBuilder\ICompositeExpression;
 
 class CompositeExpression implements ICompositeExpression, \Countable {
 	/** @var \Doctrine\DBAL\Query\Expression\CompositeExpression */
@@ -41,7 +41,7 @@ class CompositeExpression implements ICompositeExpression, \Countable {
 	 *
 	 * @param array $parts
 	 *
-	 * @return \OCP\DB\ICompositeExpression
+	 * @return \OCP\DB\QueryBuilder\ICompositeExpression
 	 */
 	public function addMultiple(array $parts = array()) {
 		$this->compositeExpression->addMultiple($parts);
@@ -54,7 +54,7 @@ class CompositeExpression implements ICompositeExpression, \Countable {
 	 *
 	 * @param mixed $part
 	 *
-	 * @return \OCP\DB\ICompositeExpression
+	 * @return \OCP\DB\QueryBuilder\ICompositeExpression
 	 */
 	public function add($part) {
 		$this->compositeExpression->add($part);
diff --git a/lib/private/db/expressionbuilder.php b/lib/private/db/querybuilder/expressionbuilder.php
similarity index 84%
rename from lib/private/db/expressionbuilder.php
rename to lib/private/db/querybuilder/expressionbuilder.php
index f042664d96..cd5b7fbfc5 100644
--- a/lib/private/db/expressionbuilder.php
+++ b/lib/private/db/querybuilder/expressionbuilder.php
@@ -19,22 +19,26 @@
  *
  */
 
-namespace OC\DB;
+namespace OC\DB\QueryBuilder;
 
 use Doctrine\DBAL\Query\Expression\ExpressionBuilder as DoctrineExpressionBuilder;
-use OCP\DB\IExpressionBuilder;
+use OCP\DB\QueryBuilder\IExpressionBuilder;
 use OCP\IDBConnection;
 
 class ExpressionBuilder implements IExpressionBuilder {
 	/** @var \Doctrine\DBAL\Query\Expression\ExpressionBuilder */
 	private $expressionBuilder;
 
+	/** @var QuoteHelper */
+	private $helper;
+
 	/**
 	 * Initializes a new <tt>ExpressionBuilder</tt>.
 	 *
 	 * @param \OCP\IDBConnection $connection
 	 */
 	public function __construct(IDBConnection $connection) {
+		$this->helper = new QuoteHelper();
 		$this->expressionBuilder = new DoctrineExpressionBuilder($connection);
 	}
 
@@ -50,10 +54,11 @@ class ExpressionBuilder implements IExpressionBuilder {
 	 * @param mixed $x Optional clause. Defaults = null, but requires
 	 *                 at least one defined when converting to string.
 	 *
-	 * @return \OCP\DB\ICompositeExpression
+	 * @return \OCP\DB\QueryBuilder\ICompositeExpression
 	 */
 	public function andX($x = null) {
-		$compositeExpression = call_user_func_array([$this->expressionBuilder, 'andX'], func_get_args());
+		$arguments = func_get_args();
+		$compositeExpression = call_user_func_array([$this->expressionBuilder, 'andX'], $arguments);
 		return new CompositeExpression($compositeExpression);
 	}
 
@@ -69,10 +74,11 @@ class ExpressionBuilder implements IExpressionBuilder {
 	 * @param mixed $x Optional clause. Defaults = null, but requires
 	 *                 at least one defined when converting to string.
 	 *
-	 * @return \OCP\DB\ICompositeExpression
+	 * @return \OCP\DB\QueryBuilder\ICompositeExpression
 	 */
 	public function orX($x = null) {
-		$compositeExpression = call_user_func_array([$this->expressionBuilder, 'orX'], func_get_args());
+		$arguments = func_get_args();
+		$compositeExpression = call_user_func_array([$this->expressionBuilder, 'orX'], $arguments);
 		return new CompositeExpression($compositeExpression);
 	}
 
@@ -86,6 +92,8 @@ class ExpressionBuilder implements IExpressionBuilder {
 	 * @return string
 	 */
 	public function comparison($x, $operator, $y) {
+		$x = $this->helper->quoteColumnName($x);
+		$y = $this->helper->quoteColumnName($y);
 		return $this->expressionBuilder->comparison($x, $operator, $y);
 	}
 
@@ -105,6 +113,8 @@ class ExpressionBuilder implements IExpressionBuilder {
 	 * @return string
 	 */
 	public function eq($x, $y) {
+		$x = $this->helper->quoteColumnName($x);
+		$y = $this->helper->quoteColumnName($y);
 		return $this->expressionBuilder->eq($x, $y);
 	}
 
@@ -123,6 +133,8 @@ class ExpressionBuilder implements IExpressionBuilder {
 	 * @return string
 	 */
 	public function neq($x, $y) {
+		$x = $this->helper->quoteColumnName($x);
+		$y = $this->helper->quoteColumnName($y);
 		return $this->expressionBuilder->neq($x, $y);
 	}
 
@@ -141,6 +153,8 @@ class ExpressionBuilder implements IExpressionBuilder {
 	 * @return string
 	 */
 	public function lt($x, $y) {
+		$x = $this->helper->quoteColumnName($x);
+		$y = $this->helper->quoteColumnName($y);
 		return $this->expressionBuilder->lt($x, $y);
 	}
 
@@ -159,6 +173,8 @@ class ExpressionBuilder implements IExpressionBuilder {
 	 * @return string
 	 */
 	public function lte($x, $y) {
+		$x = $this->helper->quoteColumnName($x);
+		$y = $this->helper->quoteColumnName($y);
 		return $this->expressionBuilder->lte($x, $y);
 	}
 
@@ -177,6 +193,8 @@ class ExpressionBuilder implements IExpressionBuilder {
 	 * @return string
 	 */
 	public function gt($x, $y) {
+		$x = $this->helper->quoteColumnName($x);
+		$y = $this->helper->quoteColumnName($y);
 		return $this->expressionBuilder->gt($x, $y);
 	}
 
@@ -195,6 +213,8 @@ class ExpressionBuilder implements IExpressionBuilder {
 	 * @return string
 	 */
 	public function gte($x, $y) {
+		$x = $this->helper->quoteColumnName($x);
+		$y = $this->helper->quoteColumnName($y);
 		return $this->expressionBuilder->gte($x, $y);
 	}
 
@@ -206,6 +226,7 @@ class ExpressionBuilder implements IExpressionBuilder {
 	 * @return string
 	 */
 	public function isNull($x) {
+		$x = $this->helper->quoteColumnName($x);
 		return $this->expressionBuilder->isNull($x);
 	}
 
@@ -217,6 +238,7 @@ class ExpressionBuilder implements IExpressionBuilder {
 	 * @return string
 	 */
 	public function isNotNull($x) {
+		$x = $this->helper->quoteColumnName($x);
 		return $this->expressionBuilder->isNotNull($x);
 	}
 
@@ -229,6 +251,8 @@ class ExpressionBuilder implements IExpressionBuilder {
 	 * @return string
 	 */
 	public function like($x, $y) {
+		$x = $this->helper->quoteColumnName($x);
+		$y = $this->helper->quoteColumnName($y);
 		return $this->expressionBuilder->like($x, $y);
 	}
 
@@ -241,6 +265,8 @@ class ExpressionBuilder implements IExpressionBuilder {
 	 * @return string
 	 */
 	public function notLike($x, $y) {
+		$x = $this->helper->quoteColumnName($x);
+		$y = $this->helper->quoteColumnName($y);
 		return $this->expressionBuilder->notLike($x, $y);
 	}
 
@@ -253,6 +279,8 @@ class ExpressionBuilder implements IExpressionBuilder {
 	 * @return string
 	 */
 	public function in($x, $y) {
+		$x = $this->helper->quoteColumnName($x);
+		$y = $this->helper->quoteColumnNames($y);
 		return $this->expressionBuilder->in($x, $y);
 	}
 
@@ -265,6 +293,8 @@ class ExpressionBuilder implements IExpressionBuilder {
 	 * @return string
 	 */
 	public function notIn($x, $y) {
+		$x = $this->helper->quoteColumnName($x);
+		$y = $this->helper->quoteColumnNames($y);
 		return $this->expressionBuilder->notIn($x, $y);
 	}
 
@@ -274,9 +304,9 @@ class ExpressionBuilder implements IExpressionBuilder {
 	 * @param mixed $input The parameter to be quoted.
 	 * @param string|null $type The type of the parameter.
 	 *
-	 * @return string
+	 * @return Literal
 	 */
 	public function literal($input, $type = null) {
-		return $this->expressionBuilder->literal($input, $type);
+		return new Literal($this->expressionBuilder->literal($input, $type));
 	}
 }
diff --git a/lib/private/db/querybuilder/literal.php b/lib/private/db/querybuilder/literal.php
new file mode 100644
index 0000000000..361b5ccf3b
--- /dev/null
+++ b/lib/private/db/querybuilder/literal.php
@@ -0,0 +1,40 @@
+<?php
+/**
+ * @author Joas Schilling <nickvergessen@owncloud.com>
+ *
+ * @copyright Copyright (c) 2015, ownCloud, Inc.
+ * @license AGPL-3.0
+ *
+ * This code is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License, version 3,
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>
+ *
+ */
+
+namespace OC\DB\QueryBuilder;
+
+use OCP\DB\QueryBuilder\ILiteral;
+
+class Literal implements ILiteral{
+	/** @var mixed */
+	protected $literal;
+
+	public function __construct($literal) {
+		$this->literal = $literal;
+	}
+
+	/**
+	 * @return string
+	 */
+	public function __toString() {
+		return (string) $this->literal;
+	}
+}
diff --git a/lib/private/db/querybuilder/parameter.php b/lib/private/db/querybuilder/parameter.php
new file mode 100644
index 0000000000..c14b4e2192
--- /dev/null
+++ b/lib/private/db/querybuilder/parameter.php
@@ -0,0 +1,40 @@
+<?php
+/**
+ * @author Joas Schilling <nickvergessen@owncloud.com>
+ *
+ * @copyright Copyright (c) 2015, ownCloud, Inc.
+ * @license AGPL-3.0
+ *
+ * This code is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License, version 3,
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>
+ *
+ */
+
+namespace OC\DB\QueryBuilder;
+
+use OCP\DB\QueryBuilder\IParameter;
+
+class Parameter implements IParameter {
+	/** @var mixed */
+	protected $name;
+
+	public function __construct($name) {
+		$this->name = $name;
+	}
+
+	/**
+	 * @return string
+	 */
+	public function __toString() {
+		return (string) $this->name;
+	}
+}
diff --git a/lib/private/db/querybuilder.php b/lib/private/db/querybuilder/querybuilder.php
similarity index 75%
rename from lib/private/db/querybuilder.php
rename to lib/private/db/querybuilder/querybuilder.php
index 9ae07aeb0f..fbb2b07bad 100644
--- a/lib/private/db/querybuilder.php
+++ b/lib/private/db/querybuilder/querybuilder.php
@@ -19,9 +19,11 @@
  *
  */
 
-namespace OC\DB;
+namespace OC\DB\QueryBuilder;
 
-use OCP\DB\IQueryBuilder;
+use OCP\DB\QueryBuilder\IQueryBuilder;
+use OCP\DB\QueryBuilder\IQueryFunction;
+use OCP\DB\QueryBuilder\IParameter;
 use OCP\IDBConnection;
 
 class QueryBuilder implements IQueryBuilder {
@@ -32,15 +34,18 @@ class QueryBuilder implements IQueryBuilder {
 	/** @var \Doctrine\DBAL\Query\QueryBuilder */
 	private $queryBuilder;
 
+	/** @var QuoteHelper */
+	private $helper;
+
 	/**
 	 * Initializes a new <tt>QueryBuilder</tt>.
 	 *
 	 * @var \OCP\IDBConnection
 	 */
-	public function __construct(IDBConnection $connection)
-	{
+	public function __construct(IDBConnection $connection) {
 		$this->connection = $connection;
 		$this->queryBuilder = new \Doctrine\DBAL\Query\QueryBuilder($this->connection);
+		$this->helper = new QuoteHelper();
 	}
 
 	/**
@@ -57,7 +62,7 @@ class QueryBuilder implements IQueryBuilder {
 	 * For more complex expression construction, consider storing the expression
 	 * builder object in a local variable.
 	 *
-	 * @return \OCP\DB\IExpressionBuilder
+	 * @return \OCP\DB\QueryBuilder\IExpressionBuilder
 	 */
 	public function expr() {
 		return $this->connection->getExpressionBuilder();
@@ -133,7 +138,7 @@ class QueryBuilder implements IQueryBuilder {
 	 * @param mixed $value The parameter value.
 	 * @param string|null $type One of the PDO::PARAM_* constants.
 	 *
-	 * @return \OCP\DB\IQueryBuilder This QueryBuilder instance.
+	 * @return \OCP\DB\QueryBuilder\IQueryBuilder This QueryBuilder instance.
 	 */
 	public function setParameter($key, $value, $type = null) {
 		$this->queryBuilder->setParameter($key, $value, $type);
@@ -158,7 +163,7 @@ class QueryBuilder implements IQueryBuilder {
 	 * @param array $params The query parameters to set.
 	 * @param array $types The query parameters types to set.
 	 *
-	 * @return \OCP\DB\IQueryBuilder This QueryBuilder instance.
+	 * @return \OCP\DB\QueryBuilder\IQueryBuilder This QueryBuilder instance.
 	 */
 	public function setParameters(array $params, array $types = array()) {
 		$this->queryBuilder->setParameters($params, $types);
@@ -211,7 +216,7 @@ class QueryBuilder implements IQueryBuilder {
 	 *
 	 * @param integer $firstResult The first result to return.
 	 *
-	 * @return \OCP\DB\IQueryBuilder This QueryBuilder instance.
+	 * @return \OCP\DB\QueryBuilder\IQueryBuilder This QueryBuilder instance.
 	 */
 	public function setFirstResult($firstResult) {
 		$this->queryBuilder->setFirstResult($firstResult);
@@ -234,7 +239,7 @@ class QueryBuilder implements IQueryBuilder {
 	 *
 	 * @param integer $maxResults The maximum number of results to retrieve.
 	 *
-	 * @return \OCP\DB\IQueryBuilder This QueryBuilder instance.
+	 * @return \OCP\DB\QueryBuilder\IQueryBuilder This QueryBuilder instance.
 	 */
 	public function setMaxResults($maxResults) {
 		$this->queryBuilder->setMaxResults($maxResults);
@@ -252,24 +257,6 @@ class QueryBuilder implements IQueryBuilder {
 		return $this->queryBuilder->getMaxResults();
 	}
 
-	/**
-	 * Either appends to or replaces a single, generic query part.
-	 *
-	 * The available parts are: 'select', 'from', 'set', 'where',
-	 * 'groupBy', 'having' and 'orderBy'.
-	 *
-	 * @param string $sqlPartName
-	 * @param string $sqlPart
-	 * @param boolean $append
-	 *
-	 * @return \OCP\DB\IQueryBuilder This QueryBuilder instance.
-	 */
-	public function add($sqlPartName, $sqlPart, $append = false) {
-		$this->queryBuilder->add($sqlPartName, $sqlPart, $append);
-
-		return $this;
-	}
-
 	/**
 	 * Specifies an item that is to be returned in the query result.
 	 * Replaces any previously specified selections, if any.
@@ -283,10 +270,14 @@ class QueryBuilder implements IQueryBuilder {
 	 *
 	 * @param mixed $select The selection expressions.
 	 *
-	 * @return \OCP\DB\IQueryBuilder This QueryBuilder instance.
+	 * @return \OCP\DB\QueryBuilder\IQueryBuilder This QueryBuilder instance.
 	 */
 	public function select($select = null) {
-		$this->queryBuilder->select($select);
+		$selects = is_array($select) ? $select : func_get_args();
+
+		$this->queryBuilder->select(
+			$this->helper->quoteColumnNames($selects)
+		);
 
 		return $this;
 	}
@@ -304,10 +295,14 @@ class QueryBuilder implements IQueryBuilder {
 	 *
 	 * @param mixed $select The selection expression.
 	 *
-	 * @return \OCP\DB\IQueryBuilder This QueryBuilder instance.
+	 * @return \OCP\DB\QueryBuilder\IQueryBuilder This QueryBuilder instance.
 	 */
 	public function addSelect($select = null) {
-		$this->queryBuilder->addSelect($select);
+		$selects = is_array($select) ? $select : func_get_args();
+
+		$this->queryBuilder->addSelect(
+			$this->helper->quoteColumnNames($selects)
+		);
 
 		return $this;
 	}
@@ -326,10 +321,13 @@ class QueryBuilder implements IQueryBuilder {
 	 * @param string $delete The table whose rows are subject to the deletion.
 	 * @param string $alias The table alias used in the constructed query.
 	 *
-	 * @return \OCP\DB\IQueryBuilder This QueryBuilder instance.
+	 * @return \OCP\DB\QueryBuilder\IQueryBuilder This QueryBuilder instance.
 	 */
 	public function delete($delete = null, $alias = null) {
-		$this->queryBuilder->delete($delete, $alias);
+		$this->queryBuilder->delete(
+			$this->helper->quoteColumnName($delete),
+			$alias
+		);
 
 		return $this;
 	}
@@ -348,10 +346,13 @@ class QueryBuilder implements IQueryBuilder {
 	 * @param string $update The table whose rows are subject to the update.
 	 * @param string $alias The table alias used in the constructed query.
 	 *
-	 * @return \OCP\DB\IQueryBuilder This QueryBuilder instance.
+	 * @return \OCP\DB\QueryBuilder\IQueryBuilder This QueryBuilder instance.
 	 */
 	public function update($update = null, $alias = null) {
-		$this->queryBuilder->update($update, $alias);
+		$this->queryBuilder->update(
+			$this->helper->quoteColumnName($update),
+			$alias
+		);
 
 		return $this;
 	}
@@ -373,10 +374,12 @@ class QueryBuilder implements IQueryBuilder {
 	 *
 	 * @param string $insert The table into which the rows should be inserted.
 	 *
-	 * @return \OCP\DB\IQueryBuilder This QueryBuilder instance.
+	 * @return \OCP\DB\QueryBuilder\IQueryBuilder This QueryBuilder instance.
 	 */
 	public function insert($insert = null) {
-		$this->queryBuilder->insert($insert);
+		$this->queryBuilder->insert(
+			$this->helper->quoteColumnName($insert)
+		);
 
 		return $this;
 	}
@@ -394,10 +397,13 @@ class QueryBuilder implements IQueryBuilder {
 	 * @param string $from The table.
 	 * @param string|null $alias The alias of the table.
 	 *
-	 * @return \OCP\DB\IQueryBuilder This QueryBuilder instance.
+	 * @return \OCP\DB\QueryBuilder\IQueryBuilder This QueryBuilder instance.
 	 */
 	public function from($from, $alias = null) {
-		$this->queryBuilder->from($from, $alias);
+		$this->queryBuilder->from(
+			$this->helper->quoteColumnName($from),
+			$alias
+		);
 
 		return $this;
 	}
@@ -417,10 +423,15 @@ class QueryBuilder implements IQueryBuilder {
 	 * @param string $alias The alias of the join table.
 	 * @param string $condition The condition for the join.
 	 *
-	 * @return \OCP\DB\IQueryBuilder This QueryBuilder instance.
+	 * @return \OCP\DB\QueryBuilder\IQueryBuilder This QueryBuilder instance.
 	 */
 	public function join($fromAlias, $join, $alias, $condition = null) {
-		$this->queryBuilder->join($fromAlias, $join, $alias, $condition);
+		$this->queryBuilder->join(
+			$fromAlias,
+			$this->helper->quoteColumnName($join),
+			$alias,
+			$condition
+		);
 
 		return $this;
 	}
@@ -440,10 +451,15 @@ class QueryBuilder implements IQueryBuilder {
 	 * @param string $alias The alias of the join table.
 	 * @param string $condition The condition for the join.
 	 *
-	 * @return \OCP\DB\IQueryBuilder This QueryBuilder instance.
+	 * @return \OCP\DB\QueryBuilder\IQueryBuilder This QueryBuilder instance.
 	 */
 	public function innerJoin($fromAlias, $join, $alias, $condition = null) {
-		$this->queryBuilder->innerJoin($fromAlias, $join, $alias, $condition);
+		$this->queryBuilder->innerJoin(
+			$fromAlias,
+			$this->helper->quoteColumnName($join),
+			$alias,
+			$condition
+		);
 
 		return $this;
 	}
@@ -463,10 +479,15 @@ class QueryBuilder implements IQueryBuilder {
 	 * @param string $alias The alias of the join table.
 	 * @param string $condition The condition for the join.
 	 *
-	 * @return \OCP\DB\IQueryBuilder This QueryBuilder instance.
+	 * @return \OCP\DB\QueryBuilder\IQueryBuilder This QueryBuilder instance.
 	 */
 	public function leftJoin($fromAlias, $join, $alias, $condition = null) {
-		$this->queryBuilder->leftJoin($fromAlias, $join, $alias, $condition);
+		$this->queryBuilder->leftJoin(
+			$fromAlias,
+			$this->helper->quoteColumnName($join),
+			$alias,
+			$condition
+		);
 
 		return $this;
 	}
@@ -486,10 +507,15 @@ class QueryBuilder implements IQueryBuilder {
 	 * @param string $alias The alias of the join table.
 	 * @param string $condition The condition for the join.
 	 *
-	 * @return \OCP\DB\IQueryBuilder This QueryBuilder instance.
+	 * @return \OCP\DB\QueryBuilder\IQueryBuilder This QueryBuilder instance.
 	 */
 	public function rightJoin($fromAlias, $join, $alias, $condition = null) {
-		$this->queryBuilder->rightJoin($fromAlias, $join, $alias, $condition);
+		$this->queryBuilder->rightJoin(
+			$fromAlias,
+			$this->helper->quoteColumnName($join),
+			$alias,
+			$condition
+		);
 
 		return $this;
 	}
@@ -507,10 +533,13 @@ class QueryBuilder implements IQueryBuilder {
 	 * @param string $key The column to set.
 	 * @param string $value The value, expression, placeholder, etc.
 	 *
-	 * @return \OCP\DB\IQueryBuilder This QueryBuilder instance.
+	 * @return \OCP\DB\QueryBuilder\IQueryBuilder This QueryBuilder instance.
 	 */
 	public function set($key, $value) {
-		$this->queryBuilder->set($key, $value);
+		$this->queryBuilder->set(
+			$this->helper->quoteColumnName($key),
+			$this->helper->quoteColumnName($value)
+		);
 
 		return $this;
 	}
@@ -539,10 +568,13 @@ class QueryBuilder implements IQueryBuilder {
 	 *
 	 * @param mixed $predicates The restriction predicates.
 	 *
-	 * @return \OCP\DB\IQueryBuilder This QueryBuilder instance.
+	 * @return \OCP\DB\QueryBuilder\IQueryBuilder This QueryBuilder instance.
 	 */
 	public function where($predicates) {
-		call_user_func_array([$this->queryBuilder, 'where'], func_get_args());
+		call_user_func_array(
+			[$this->queryBuilder, 'where'],
+			func_get_args()
+		);
 
 		return $this;
 	}
@@ -561,12 +593,15 @@ class QueryBuilder implements IQueryBuilder {
 	 *
 	 * @param mixed $where The query restrictions.
 	 *
-	 * @return \OCP\DB\IQueryBuilder This QueryBuilder instance.
+	 * @return \OCP\DB\QueryBuilder\IQueryBuilder This QueryBuilder instance.
 	 *
 	 * @see where()
 	 */
 	public function andWhere($where) {
-		call_user_func_array([$this->queryBuilder, 'andWhere'], func_get_args());
+		call_user_func_array(
+			[$this->queryBuilder, 'andWhere'],
+			func_get_args()
+		);
 
 		return $this;
 	}
@@ -585,12 +620,15 @@ class QueryBuilder implements IQueryBuilder {
 	 *
 	 * @param mixed $where The WHERE statement.
 	 *
-	 * @return \OCP\DB\IQueryBuilder This QueryBuilder instance.
+	 * @return \OCP\DB\QueryBuilder\IQueryBuilder This QueryBuilder instance.
 	 *
 	 * @see where()
 	 */
 	public function orWhere($where) {
-		call_user_func_array([$this->queryBuilder, 'orWhere'], func_get_args());
+		call_user_func_array(
+			[$this->queryBuilder, 'orWhere'],
+			func_get_args()
+		);
 
 		return $this;
 	}
@@ -608,10 +646,15 @@ class QueryBuilder implements IQueryBuilder {
 	 *
 	 * @param mixed $groupBy The grouping expression.
 	 *
-	 * @return \OCP\DB\IQueryBuilder This QueryBuilder instance.
+	 * @return \OCP\DB\QueryBuilder\IQueryBuilder This QueryBuilder instance.
 	 */
 	public function groupBy($groupBy) {
-		call_user_func_array([$this->queryBuilder, 'groupBy'], func_get_args());
+		$groupBys = is_array($groupBy) ? $groupBy : func_get_args();
+
+		call_user_func_array(
+			[$this->queryBuilder, 'groupBy'],
+			$this->helper->quoteColumnNames($groupBys)
+		);
 
 		return $this;
 	}
@@ -629,10 +672,15 @@ class QueryBuilder implements IQueryBuilder {
 	 *
 	 * @param mixed $groupBy The grouping expression.
 	 *
-	 * @return \OCP\DB\IQueryBuilder This QueryBuilder instance.
+	 * @return \OCP\DB\QueryBuilder\IQueryBuilder This QueryBuilder instance.
 	 */
 	public function addGroupBy($groupBy) {
-		call_user_func_array([$this->queryBuilder, 'addGroupBy'], func_get_args());
+		$groupBys = is_array($groupBy) ? $groupBy : func_get_args();
+
+		call_user_func_array(
+			[$this->queryBuilder, 'addGroupBy'],
+			$this->helper->quoteColumnNames($groupBys)
+		);
 
 		return $this;
 	}
@@ -654,10 +702,13 @@ class QueryBuilder implements IQueryBuilder {
 	 * @param string $column The column into which the value should be inserted.
 	 * @param string $value The value that should be inserted into the column.
 	 *
-	 * @return \OCP\DB\IQueryBuilder This QueryBuilder instance.
+	 * @return \OCP\DB\QueryBuilder\IQueryBuilder This QueryBuilder instance.
 	 */
 	public function setValue($column, $value) {
-		$this->queryBuilder->setValue($column, $value);
+		$this->queryBuilder->setValue(
+			$this->helper->quoteColumnName($column),
+			$value
+		);
 
 		return $this;
 	}
@@ -679,10 +730,15 @@ class QueryBuilder implements IQueryBuilder {
 	 *
 	 * @param array $values The values to specify for the insert query indexed by column names.
 	 *
-	 * @return \OCP\DB\IQueryBuilder This QueryBuilder instance.
+	 * @return \OCP\DB\QueryBuilder\IQueryBuilder This QueryBuilder instance.
 	 */
 	public function values(array $values) {
-		$this->queryBuilder->values($values);
+		$quotedValues = [];
+		foreach ($values as $key => $value) {
+			$quotedValues[$this->helper->quoteColumnName($key)] = $value;
+		}
+
+		$this->queryBuilder->values($quotedValues);
 
 		return $this;
 	}
@@ -693,10 +749,13 @@ class QueryBuilder implements IQueryBuilder {
 	 *
 	 * @param mixed $having The restriction over the groups.
 	 *
-	 * @return \OCP\DB\IQueryBuilder This QueryBuilder instance.
+	 * @return \OCP\DB\QueryBuilder\IQueryBuilder This QueryBuilder instance.
 	 */
 	public function having($having) {
-		call_user_func_array([$this->queryBuilder, 'having'], func_get_args());
+		call_user_func_array(
+			[$this->queryBuilder, 'having'],
+			func_get_args()
+		);
 
 		return $this;
 	}
@@ -707,10 +766,13 @@ class QueryBuilder implements IQueryBuilder {
 	 *
 	 * @param mixed $having The restriction to append.
 	 *
-	 * @return \OCP\DB\IQueryBuilder This QueryBuilder instance.
+	 * @return \OCP\DB\QueryBuilder\IQueryBuilder This QueryBuilder instance.
 	 */
 	public function andHaving($having) {
-		call_user_func_array([$this->queryBuilder, 'andHaving'], func_get_args());
+		call_user_func_array(
+			[$this->queryBuilder, 'andHaving'],
+			func_get_args()
+		);
 
 		return $this;
 	}
@@ -721,10 +783,13 @@ class QueryBuilder implements IQueryBuilder {
 	 *
 	 * @param mixed $having The restriction to add.
 	 *
-	 * @return \OCP\DB\IQueryBuilder This QueryBuilder instance.
+	 * @return \OCP\DB\QueryBuilder\IQueryBuilder This QueryBuilder instance.
 	 */
 	public function orHaving($having) {
-		call_user_func_array([$this->queryBuilder, 'orHaving'], func_get_args());
+		call_user_func_array(
+			[$this->queryBuilder, 'orHaving'],
+			func_get_args()
+		);
 
 		return $this;
 	}
@@ -736,10 +801,13 @@ class QueryBuilder implements IQueryBuilder {
 	 * @param string $sort The ordering expression.
 	 * @param string $order The ordering direction.
 	 *
-	 * @return \OCP\DB\IQueryBuilder This QueryBuilder instance.
+	 * @return \OCP\DB\QueryBuilder\IQueryBuilder This QueryBuilder instance.
 	 */
 	public function orderBy($sort, $order = null) {
-		$this->queryBuilder->orderBy($sort, $order);
+		$this->queryBuilder->orderBy(
+			$this->helper->quoteColumnName($sort),
+			$order
+		);
 
 		return $this;
 	}
@@ -750,10 +818,13 @@ class QueryBuilder implements IQueryBuilder {
 	 * @param string $sort The ordering expression.
 	 * @param string $order The ordering direction.
 	 *
-	 * @return \OCP\DB\IQueryBuilder This QueryBuilder instance.
+	 * @return \OCP\DB\QueryBuilder\IQueryBuilder This QueryBuilder instance.
 	 */
 	public function addOrderBy($sort, $order = null) {
-		$this->queryBuilder->addOrderBy($sort, $order);
+		$this->queryBuilder->addOrderBy(
+			$this->helper->quoteColumnName($sort),
+			$order
+		);
 
 		return $this;
 	}
@@ -783,7 +854,7 @@ class QueryBuilder implements IQueryBuilder {
 	 *
 	 * @param array|null $queryPartNames
 	 *
-	 * @return \OCP\DB\IQueryBuilder This QueryBuilder instance.
+	 * @return \OCP\DB\QueryBuilder\IQueryBuilder This QueryBuilder instance.
 	 */
 	public function resetQueryParts($queryPartNames = null) {
 		$this->queryBuilder->resetQueryParts($queryPartNames);
@@ -796,7 +867,7 @@ class QueryBuilder implements IQueryBuilder {
 	 *
 	 * @param string $queryPartName
 	 *
-	 * @return \OCP\DB\IQueryBuilder This QueryBuilder instance.
+	 * @return \OCP\DB\QueryBuilder\IQueryBuilder This QueryBuilder instance.
 	 */
 	public function resetQueryPart($queryPartName) {
 		$this->queryBuilder->resetQueryPart($queryPartName);
@@ -831,10 +902,10 @@ class QueryBuilder implements IQueryBuilder {
 	 * @param mixed $type
 	 * @param string $placeHolder The name to bind with. The string must start with a colon ':'.
 	 *
-	 * @return string the placeholder name used.
+	 * @return IParameter the placeholder name used.
 	 */
 	public function createNamedParameter($value, $type = \PDO::PARAM_STR, $placeHolder = null) {
-		return $this->queryBuilder->createNamedParameter($value, $type, $placeHolder);
+		return new Parameter($this->queryBuilder->createNamedParameter($value, $type, $placeHolder));
 	}
 
 	/**
@@ -857,9 +928,56 @@ class QueryBuilder implements IQueryBuilder {
 	 * @param mixed $value
 	 * @param integer $type
 	 *
-	 * @return string
+	 * @return IParameter
 	 */
 	public function createPositionalParameter($value, $type = \PDO::PARAM_STR) {
-		return $this->queryBuilder->createPositionalParameter($value, $type);
+		return new Parameter($this->queryBuilder->createPositionalParameter($value, $type));
+	}
+
+	/**
+	 * Creates a new parameter
+	 *
+	 * Example:
+	 * <code>
+	 *  $qb = $conn->getQueryBuilder();
+	 *  $qb->select('u.*')
+	 *     ->from('users', 'u')
+	 *     ->where('u.username = ' . $qb->createParameter('name'))
+	 *     ->setParameter('name', 'Bar', PDO::PARAM_STR))
+	 * </code>
+	 *
+	 * @param string $name
+	 *
+	 * @return IParameter
+	 */
+	public function createParameter($name) {
+		return new Parameter(':' . $name);
+	}
+
+	/**
+	 * Creates a new function
+	 *
+	 * Attention: Column names inside the call have to be quoted before hand
+	 *
+	 * Example:
+	 * <code>
+	 *  $qb = $conn->getQueryBuilder();
+	 *  $qb->select($qb->createFunction('COUNT(*)'))
+	 *     ->from('users', 'u')
+	 *  echo $qb->getSQL(); // SELECT COUNT(*) FROM `users` u
+	 * </code>
+	 * <code>
+	 *  $qb = $conn->getQueryBuilder();
+	 *  $qb->select($qb->createFunction('COUNT(`column`)'))
+	 *     ->from('users', 'u')
+	 *  echo $qb->getSQL(); // SELECT COUNT(`column`) FROM `users` u
+	 * </code>
+	 *
+	 * @param string $call
+	 *
+	 * @return IQueryFunction
+	 */
+	public function createFunction($call) {
+		return new QueryFunction($call);
 	}
 }
diff --git a/lib/private/db/querybuilder/queryfunction.php b/lib/private/db/querybuilder/queryfunction.php
new file mode 100644
index 0000000000..2a47d83b91
--- /dev/null
+++ b/lib/private/db/querybuilder/queryfunction.php
@@ -0,0 +1,40 @@
+<?php
+/**
+ * @author Joas Schilling <nickvergessen@owncloud.com>
+ *
+ * @copyright Copyright (c) 2015, ownCloud, Inc.
+ * @license AGPL-3.0
+ *
+ * This code is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License, version 3,
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>
+ *
+ */
+
+namespace OC\DB\QueryBuilder;
+
+use OCP\DB\QueryBuilder\IQueryFunction;
+
+class QueryFunction implements IQueryFunction {
+	/** @var string */
+	protected $function;
+
+	public function __construct($function) {
+		$this->function = $function;
+	}
+
+	/**
+	 * @return string
+	 */
+	public function __toString() {
+		return (string) $this->function;
+	}
+}
diff --git a/lib/private/db/querybuilder/quotehelper.php b/lib/private/db/querybuilder/quotehelper.php
new file mode 100644
index 0000000000..0735f313ab
--- /dev/null
+++ b/lib/private/db/querybuilder/quotehelper.php
@@ -0,0 +1,75 @@
+<?php
+/**
+ * @author Joas Schilling <nickvergessen@owncloud.com>
+ *
+ * @copyright Copyright (c) 2015, ownCloud, Inc.
+ * @license AGPL-3.0
+ *
+ * This code is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License, version 3,
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>
+ *
+ */
+
+namespace OC\DB\QueryBuilder;
+
+use OCP\DB\QueryBuilder\ILiteral;
+use OCP\DB\QueryBuilder\IParameter;
+use OCP\DB\QueryBuilder\IQueryFunction;
+
+class QuoteHelper {
+	/**
+	 * @param array|string|ILiteral|IParameter|IQueryFunction $strings string, Literal or Parameter
+	 * @return array|string
+	 */
+	public function quoteColumnNames($strings) {
+		if (!is_array($strings)) {
+			return $this->quoteColumnName($strings);
+		}
+
+		$return = [];
+		foreach ($strings as $string) {
+			$return[] = $this->quoteColumnName($string);
+		}
+
+		return $return;
+	}
+
+	/**
+	 * @param string|ILiteral|IParameter|IQueryFunction $string string, Literal or Parameter
+	 * @return string
+	 */
+	public function quoteColumnName($string) {
+		if ($string instanceof IParameter || $string instanceof ILiteral || $string instanceof IQueryFunction) {
+			return (string) $string;
+		}
+
+		if ($string === null || $string === '*') {
+			return $string;
+		}
+
+		if (!is_string($string)) {
+			throw new \InvalidArgumentException('Only strings, Literals and Parameters are allowed');
+		}
+
+		if (substr_count($string, '.')) {
+			list($alias, $columnName) = explode('.', $string);
+
+			if ($columnName === '*') {
+				return $string;
+			}
+
+			return $alias . '.`' . $columnName . '`';
+		}
+
+		return '`' . $string . '`';
+	}
+}
diff --git a/lib/public/db/icompositeexpression.php b/lib/public/db/querybuilder/icompositeexpression.php
similarity index 98%
rename from lib/public/db/icompositeexpression.php
rename to lib/public/db/querybuilder/icompositeexpression.php
index 123e4ca7cc..439c0ab20a 100644
--- a/lib/public/db/icompositeexpression.php
+++ b/lib/public/db/querybuilder/icompositeexpression.php
@@ -19,7 +19,7 @@
  *
  */
 
-namespace OCP\DB;
+namespace OCP\DB\QueryBuilder;
 
 /**
  * This class provides a wrapper around Doctrine's CompositeExpression
diff --git a/lib/public/db/iexpressionbuilder.php b/lib/public/db/querybuilder/iexpressionbuilder.php
similarity index 98%
rename from lib/public/db/iexpressionbuilder.php
rename to lib/public/db/querybuilder/iexpressionbuilder.php
index 848a8a2f8f..d719f07ebd 100644
--- a/lib/public/db/iexpressionbuilder.php
+++ b/lib/public/db/querybuilder/iexpressionbuilder.php
@@ -19,7 +19,7 @@
  *
  */
 
-namespace OCP\DB;
+namespace OCP\DB\QueryBuilder;
 
 /**
  * This class provides a wrapper around Doctrine's ExpressionBuilder
@@ -38,7 +38,7 @@ interface IExpressionBuilder {
 	 * @param mixed $x Optional clause. Defaults = null, but requires
 	 *                 at least one defined when converting to string.
 	 *
-	 * @return \OCP\DB\ICompositeExpression
+	 * @return \OCP\DB\QueryBuilder\ICompositeExpression
 	 * @since 8.2.0
 	 */
 	public function andX($x = null);
@@ -55,7 +55,7 @@ interface IExpressionBuilder {
 	 * @param mixed $x Optional clause. Defaults = null, but requires
 	 *                 at least one defined when converting to string.
 	 *
-	 * @return \OCP\DB\ICompositeExpression
+	 * @return \OCP\DB\QueryBuilder\ICompositeExpression
 	 * @since 8.2.0
 	 */
 	public function orX($x = null);
diff --git a/lib/public/db/querybuilder/iliteral.php b/lib/public/db/querybuilder/iliteral.php
new file mode 100644
index 0000000000..a09b25bb2b
--- /dev/null
+++ b/lib/public/db/querybuilder/iliteral.php
@@ -0,0 +1,29 @@
+<?php
+/**
+ * @author Joas Schilling <nickvergessen@owncloud.com>
+ *
+ * @copyright Copyright (c) 2015, ownCloud, Inc.
+ * @license AGPL-3.0
+ *
+ * This code is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License, version 3,
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>
+ *
+ */
+namespace OCP\DB\QueryBuilder;
+
+interface ILiteral {
+	/**
+	 * @return string
+	 * @since 8.2.0
+	 */
+	public function __toString();
+}
diff --git a/lib/public/db/querybuilder/iparameter.php b/lib/public/db/querybuilder/iparameter.php
new file mode 100644
index 0000000000..0eb525b352
--- /dev/null
+++ b/lib/public/db/querybuilder/iparameter.php
@@ -0,0 +1,29 @@
+<?php
+/**
+ * @author Joas Schilling <nickvergessen@owncloud.com>
+ *
+ * @copyright Copyright (c) 2015, ownCloud, Inc.
+ * @license AGPL-3.0
+ *
+ * This code is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License, version 3,
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>
+ *
+ */
+namespace OCP\DB\QueryBuilder;
+
+interface IParameter {
+	/**
+	 * @return string
+	 * @since 8.2.0
+	 */
+	public function __toString();
+}
diff --git a/lib/public/db/iquerybuilder.php b/lib/public/db/querybuilder/iquerybuilder.php
similarity index 84%
rename from lib/public/db/iquerybuilder.php
rename to lib/public/db/querybuilder/iquerybuilder.php
index 24ca96c578..09d5d199be 100644
--- a/lib/public/db/iquerybuilder.php
+++ b/lib/public/db/querybuilder/iquerybuilder.php
@@ -19,7 +19,7 @@
  *
  */
 
-namespace OCP\DB;
+namespace OCP\DB\QueryBuilder;
 
 /**
  * This class provides a wrapper around Doctrine's QueryBuilder
@@ -40,7 +40,7 @@ interface IQueryBuilder {
 	 * For more complex expression construction, consider storing the expression
 	 * builder object in a local variable.
 	 *
-	 * @return \OCP\DB\IExpressionBuilder
+	 * @return \OCP\DB\QueryBuilder\IExpressionBuilder
 	 * @since 8.2.0
 	 */
 	public function expr();
@@ -110,7 +110,7 @@ interface IQueryBuilder {
 	 * @param mixed $value The parameter value.
 	 * @param string|null $type One of the PDO::PARAM_* constants.
 	 *
-	 * @return \OCP\DB\IQueryBuilder This QueryBuilder instance.
+	 * @return \OCP\DB\QueryBuilder\IQueryBuilder This QueryBuilder instance.
 	 * @since 8.2.0
 	 */
 	public function setParameter($key, $value, $type = null);
@@ -132,7 +132,7 @@ interface IQueryBuilder {
 	 * @param array $params The query parameters to set.
 	 * @param array $types The query parameters types to set.
 	 *
-	 * @return \OCP\DB\IQueryBuilder This QueryBuilder instance.
+	 * @return \OCP\DB\QueryBuilder\IQueryBuilder This QueryBuilder instance.
 	 * @since 8.2.0
 	 */
 	public function setParameters(array $params, array $types = array());
@@ -178,7 +178,7 @@ interface IQueryBuilder {
 	 *
 	 * @param integer $firstResult The first result to return.
 	 *
-	 * @return \OCP\DB\IQueryBuilder This QueryBuilder instance.
+	 * @return \OCP\DB\QueryBuilder\IQueryBuilder This QueryBuilder instance.
 	 * @since 8.2.0
 	 */
 	public function setFirstResult($firstResult);
@@ -197,7 +197,7 @@ interface IQueryBuilder {
 	 *
 	 * @param integer $maxResults The maximum number of results to retrieve.
 	 *
-	 * @return \OCP\DB\IQueryBuilder This QueryBuilder instance.
+	 * @return \OCP\DB\QueryBuilder\IQueryBuilder This QueryBuilder instance.
 	 * @since 8.2.0
 	 */
 	public function setMaxResults($maxResults);
@@ -211,21 +211,6 @@ interface IQueryBuilder {
 	 */
 	public function getMaxResults();
 
-	/**
-	 * Either appends to or replaces a single, generic query part.
-	 *
-	 * The available parts are: 'select', 'from', 'set', 'where',
-	 * 'groupBy', 'having' and 'orderBy'.
-	 *
-	 * @param string $sqlPartName
-	 * @param string $sqlPart
-	 * @param boolean $append
-	 *
-	 * @return \OCP\DB\IQueryBuilder This QueryBuilder instance.
-	 * @since 8.2.0
-	 */
-	public function add($sqlPartName, $sqlPart, $append = false);
-
 	/**
 	 * Specifies an item that is to be returned in the query result.
 	 * Replaces any previously specified selections, if any.
@@ -239,7 +224,7 @@ interface IQueryBuilder {
 	 *
 	 * @param mixed $select The selection expressions.
 	 *
-	 * @return \OCP\DB\IQueryBuilder This QueryBuilder instance.
+	 * @return \OCP\DB\QueryBuilder\IQueryBuilder This QueryBuilder instance.
 	 * @since 8.2.0
 	 */
 	public function select($select = null);
@@ -257,7 +242,7 @@ interface IQueryBuilder {
 	 *
 	 * @param mixed $select The selection expression.
 	 *
-	 * @return \OCP\DB\IQueryBuilder This QueryBuilder instance.
+	 * @return \OCP\DB\QueryBuilder\IQueryBuilder This QueryBuilder instance.
 	 * @since 8.2.0
 	 */
 	public function addSelect($select = null);
@@ -276,7 +261,7 @@ interface IQueryBuilder {
 	 * @param string $delete The table whose rows are subject to the deletion.
 	 * @param string $alias The table alias used in the constructed query.
 	 *
-	 * @return \OCP\DB\IQueryBuilder This QueryBuilder instance.
+	 * @return \OCP\DB\QueryBuilder\IQueryBuilder This QueryBuilder instance.
 	 * @since 8.2.0
 	 */
 	public function delete($delete = null, $alias = null);
@@ -295,7 +280,7 @@ interface IQueryBuilder {
 	 * @param string $update The table whose rows are subject to the update.
 	 * @param string $alias The table alias used in the constructed query.
 	 *
-	 * @return \OCP\DB\IQueryBuilder This QueryBuilder instance.
+	 * @return \OCP\DB\QueryBuilder\IQueryBuilder This QueryBuilder instance.
 	 * @since 8.2.0
 	 */
 	public function update($update = null, $alias = null);
@@ -317,7 +302,7 @@ interface IQueryBuilder {
 	 *
 	 * @param string $insert The table into which the rows should be inserted.
 	 *
-	 * @return \OCP\DB\IQueryBuilder This QueryBuilder instance.
+	 * @return \OCP\DB\QueryBuilder\IQueryBuilder This QueryBuilder instance.
 	 * @since 8.2.0
 	 */
 	public function insert($insert = null);
@@ -335,7 +320,7 @@ interface IQueryBuilder {
 	 * @param string $from The table.
 	 * @param string|null $alias The alias of the table.
 	 *
-	 * @return \OCP\DB\IQueryBuilder This QueryBuilder instance.
+	 * @return \OCP\DB\QueryBuilder\IQueryBuilder This QueryBuilder instance.
 	 * @since 8.2.0
 	 */
 	public function from($from, $alias = null);
@@ -355,7 +340,7 @@ interface IQueryBuilder {
 	 * @param string $alias The alias of the join table.
 	 * @param string $condition The condition for the join.
 	 *
-	 * @return \OCP\DB\IQueryBuilder This QueryBuilder instance.
+	 * @return \OCP\DB\QueryBuilder\IQueryBuilder This QueryBuilder instance.
 	 * @since 8.2.0
 	 */
 	public function join($fromAlias, $join, $alias, $condition = null);
@@ -375,7 +360,7 @@ interface IQueryBuilder {
 	 * @param string $alias The alias of the join table.
 	 * @param string $condition The condition for the join.
 	 *
-	 * @return \OCP\DB\IQueryBuilder This QueryBuilder instance.
+	 * @return \OCP\DB\QueryBuilder\IQueryBuilder This QueryBuilder instance.
 	 * @since 8.2.0
 	 */
 	public function innerJoin($fromAlias, $join, $alias, $condition = null);
@@ -395,7 +380,7 @@ interface IQueryBuilder {
 	 * @param string $alias The alias of the join table.
 	 * @param string $condition The condition for the join.
 	 *
-	 * @return \OCP\DB\IQueryBuilder This QueryBuilder instance.
+	 * @return \OCP\DB\QueryBuilder\IQueryBuilder This QueryBuilder instance.
 	 * @since 8.2.0
 	 */
 	public function leftJoin($fromAlias, $join, $alias, $condition = null);
@@ -415,7 +400,7 @@ interface IQueryBuilder {
 	 * @param string $alias The alias of the join table.
 	 * @param string $condition The condition for the join.
 	 *
-	 * @return \OCP\DB\IQueryBuilder This QueryBuilder instance.
+	 * @return \OCP\DB\QueryBuilder\IQueryBuilder This QueryBuilder instance.
 	 * @since 8.2.0
 	 */
 	public function rightJoin($fromAlias, $join, $alias, $condition = null);
@@ -433,7 +418,7 @@ interface IQueryBuilder {
 	 * @param string $key The column to set.
 	 * @param string $value The value, expression, placeholder, etc.
 	 *
-	 * @return \OCP\DB\IQueryBuilder This QueryBuilder instance.
+	 * @return \OCP\DB\QueryBuilder\IQueryBuilder This QueryBuilder instance.
 	 * @since 8.2.0
 	 */
 	public function set($key, $value);
@@ -462,7 +447,7 @@ interface IQueryBuilder {
 	 *
 	 * @param mixed $predicates The restriction predicates.
 	 *
-	 * @return \OCP\DB\IQueryBuilder This QueryBuilder instance.
+	 * @return \OCP\DB\QueryBuilder\IQueryBuilder This QueryBuilder instance.
 	 * @since 8.2.0
 	 */
 	public function where($predicates);
@@ -481,7 +466,7 @@ interface IQueryBuilder {
 	 *
 	 * @param mixed $where The query restrictions.
 	 *
-	 * @return \OCP\DB\IQueryBuilder This QueryBuilder instance.
+	 * @return \OCP\DB\QueryBuilder\IQueryBuilder This QueryBuilder instance.
 	 *
 	 * @see where()
 	 * @since 8.2.0
@@ -502,7 +487,7 @@ interface IQueryBuilder {
 	 *
 	 * @param mixed $where The WHERE statement.
 	 *
-	 * @return \OCP\DB\IQueryBuilder This QueryBuilder instance.
+	 * @return \OCP\DB\QueryBuilder\IQueryBuilder This QueryBuilder instance.
 	 *
 	 * @see where()
 	 * @since 8.2.0
@@ -522,7 +507,7 @@ interface IQueryBuilder {
 	 *
 	 * @param mixed $groupBy The grouping expression.
 	 *
-	 * @return \OCP\DB\IQueryBuilder This QueryBuilder instance.
+	 * @return \OCP\DB\QueryBuilder\IQueryBuilder This QueryBuilder instance.
 	 * @since 8.2.0
 	 */
 	public function groupBy($groupBy);
@@ -540,7 +525,7 @@ interface IQueryBuilder {
 	 *
 	 * @param mixed $groupBy The grouping expression.
 	 *
-	 * @return \OCP\DB\IQueryBuilder This QueryBuilder instance.
+	 * @return \OCP\DB\QueryBuilder\IQueryBuilder This QueryBuilder instance.
 	 * @since 8.2.0
 	 */
 	public function addGroupBy($groupBy);
@@ -562,7 +547,7 @@ interface IQueryBuilder {
 	 * @param string $column The column into which the value should be inserted.
 	 * @param string $value The value that should be inserted into the column.
 	 *
-	 * @return \OCP\DB\IQueryBuilder This QueryBuilder instance.
+	 * @return \OCP\DB\QueryBuilder\IQueryBuilder This QueryBuilder instance.
 	 * @since 8.2.0
 	 */
 	public function setValue($column, $value);
@@ -584,7 +569,7 @@ interface IQueryBuilder {
 	 *
 	 * @param array $values The values to specify for the insert query indexed by column names.
 	 *
-	 * @return \OCP\DB\IQueryBuilder This QueryBuilder instance.
+	 * @return \OCP\DB\QueryBuilder\IQueryBuilder This QueryBuilder instance.
 	 * @since 8.2.0
 	 */
 	public function values(array $values);
@@ -595,7 +580,7 @@ interface IQueryBuilder {
 	 *
 	 * @param mixed $having The restriction over the groups.
 	 *
-	 * @return \OCP\DB\IQueryBuilder This QueryBuilder instance.
+	 * @return \OCP\DB\QueryBuilder\IQueryBuilder This QueryBuilder instance.
 	 * @since 8.2.0
 	 */
 	public function having($having);
@@ -606,7 +591,7 @@ interface IQueryBuilder {
 	 *
 	 * @param mixed $having The restriction to append.
 	 *
-	 * @return \OCP\DB\IQueryBuilder This QueryBuilder instance.
+	 * @return \OCP\DB\QueryBuilder\IQueryBuilder This QueryBuilder instance.
 	 * @since 8.2.0
 	 */
 	public function andHaving($having);
@@ -617,7 +602,7 @@ interface IQueryBuilder {
 	 *
 	 * @param mixed $having The restriction to add.
 	 *
-	 * @return \OCP\DB\IQueryBuilder This QueryBuilder instance.
+	 * @return \OCP\DB\QueryBuilder\IQueryBuilder This QueryBuilder instance.
 	 * @since 8.2.0
 	 */
 	public function orHaving($having);
@@ -629,7 +614,7 @@ interface IQueryBuilder {
 	 * @param string $sort The ordering expression.
 	 * @param string $order The ordering direction.
 	 *
-	 * @return \OCP\DB\IQueryBuilder This QueryBuilder instance.
+	 * @return \OCP\DB\QueryBuilder\IQueryBuilder This QueryBuilder instance.
 	 * @since 8.2.0
 	 */
 	public function orderBy($sort, $order = null);
@@ -640,7 +625,7 @@ interface IQueryBuilder {
 	 * @param string $sort The ordering expression.
 	 * @param string $order The ordering direction.
 	 *
-	 * @return \OCP\DB\IQueryBuilder This QueryBuilder instance.
+	 * @return \OCP\DB\QueryBuilder\IQueryBuilder This QueryBuilder instance.
 	 * @since 8.2.0
 	 */
 	public function addOrderBy($sort, $order = null);
@@ -668,7 +653,7 @@ interface IQueryBuilder {
 	 *
 	 * @param array|null $queryPartNames
 	 *
-	 * @return \OCP\DB\IQueryBuilder This QueryBuilder instance.
+	 * @return \OCP\DB\QueryBuilder\IQueryBuilder This QueryBuilder instance.
 	 * @since 8.2.0
 	 */
 	public function resetQueryParts($queryPartNames = null);
@@ -678,7 +663,7 @@ interface IQueryBuilder {
 	 *
 	 * @param string $queryPartName
 	 *
-	 * @return \OCP\DB\IQueryBuilder This QueryBuilder instance.
+	 * @return \OCP\DB\QueryBuilder\IQueryBuilder This QueryBuilder instance.
 	 * @since 8.2.0
 	 */
 	public function resetQueryPart($queryPartName);
@@ -710,7 +695,7 @@ interface IQueryBuilder {
 	 * @param mixed $type
 	 * @param string $placeHolder The name to bind with. The string must start with a colon ':'.
 	 *
-	 * @return string the placeholder name used.
+	 * @return IParameter
 	 * @since 8.2.0
 	 */
 	public function createNamedParameter($value, $type = \PDO::PARAM_STR, $placeHolder = null);
@@ -735,8 +720,53 @@ interface IQueryBuilder {
 	 * @param mixed $value
 	 * @param integer $type
 	 *
-	 * @return string
+	 * @return IParameter
 	 * @since 8.2.0
 	 */
 	public function createPositionalParameter($value, $type = \PDO::PARAM_STR);
+
+	/**
+	 * Creates a new parameter
+	 *
+	 * Example:
+	 * <code>
+	 *  $qb = $conn->getQueryBuilder();
+	 *  $qb->select('u.*')
+	 *     ->from('users', 'u')
+	 *     ->where('u.username = ' . $qb->createParameter('name'))
+	 *     ->setParameter('name', 'Bar', PDO::PARAM_STR))
+	 * </code>
+	 *
+	 * @param string $name
+	 *
+	 * @return IParameter
+	 * @since 8.2.0
+	 */
+	public function createParameter($name);
+
+	/**
+	 * Creates a new function
+	 *
+	 * Attention: Column names inside the call have to be quoted before hand
+	 *
+	 * Example:
+	 * <code>
+	 *  $qb = $conn->getQueryBuilder();
+	 *  $qb->select($qb->createFunction('COUNT(*)'))
+	 *     ->from('users', 'u')
+	 *  echo $qb->getSQL(); // SELECT COUNT(*) FROM `users` u
+	 * </code>
+	 * <code>
+	 *  $qb = $conn->getQueryBuilder();
+	 *  $qb->select($qb->createFunction('COUNT(`column`)'))
+	 *     ->from('users', 'u')
+	 *  echo $qb->getSQL(); // SELECT COUNT(`column`) FROM `users` u
+	 * </code>
+	 *
+	 * @param string $call
+	 *
+	 * @return IQueryFunction
+	 * @since 8.2.0
+	 */
+	public function createFunction($call);
 }
diff --git a/lib/public/db/querybuilder/iqueryfunction.php b/lib/public/db/querybuilder/iqueryfunction.php
new file mode 100644
index 0000000000..499b6e1efc
--- /dev/null
+++ b/lib/public/db/querybuilder/iqueryfunction.php
@@ -0,0 +1,29 @@
+<?php
+/**
+ * @author Joas Schilling <nickvergessen@owncloud.com>
+ *
+ * @copyright Copyright (c) 2015, ownCloud, Inc.
+ * @license AGPL-3.0
+ *
+ * This code is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License, version 3,
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>
+ *
+ */
+namespace OCP\DB\QueryBuilder;
+
+interface IQueryFunction {
+	/**
+	 * @return string
+	 * @since 8.2.0
+	 */
+	public function __toString();
+}
diff --git a/lib/public/idbconnection.php b/lib/public/idbconnection.php
index a4be3acd2e..7c94611a68 100644
--- a/lib/public/idbconnection.php
+++ b/lib/public/idbconnection.php
@@ -43,7 +43,7 @@ interface IDBConnection {
 	/**
 	 * Gets the ExpressionBuilder for the connection.
 	 *
-	 * @return \OCP\DB\IExpressionBuilder
+	 * @return \OCP\DB\QueryBuilder\IExpressionBuilder
 	 * @since 8.2.0
 	 */
 	public function getExpressionBuilder();
@@ -51,7 +51,7 @@ interface IDBConnection {
 	/**
 	 * Gets the QueryBuilder for the connection.
 	 *
-	 * @return \OCP\DB\IQueryBuilder
+	 * @return \OCP\DB\QueryBuilder\IQueryBuilder
 	 * @since 8.2.0
 	 */
 	public function getQueryBuilder();
diff --git a/tests/lib/db/querybuilder/expressionbuildertest.php b/tests/lib/db/querybuilder/expressionbuildertest.php
new file mode 100644
index 0000000000..b4159e4981
--- /dev/null
+++ b/tests/lib/db/querybuilder/expressionbuildertest.php
@@ -0,0 +1,338 @@
+<?php
+/**
+ * @author Joas Schilling <nickvergessen@owncloud.com>
+ *
+ * @copyright Copyright (c) 2015, ownCloud, Inc.
+ * @license AGPL-3.0
+ *
+ * This code is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License, version 3,
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>
+ *
+ */
+
+namespace Test\DB\QueryBuilder;
+
+use Doctrine\DBAL\Query\Expression\ExpressionBuilder as DoctrineExpressionBuilder;
+use OC\DB\QueryBuilder\ExpressionBuilder;
+
+class ExpressionBuilderTest extends \Test\TestCase {
+	/** @var ExpressionBuilder */
+	protected $expressionBuilder;
+
+	/** @var DoctrineExpressionBuilder */
+	protected $doctrineExpressionBuilder;
+
+	protected function setUp() {
+		parent::setUp();
+
+		$connection = \OC::$server->getDatabaseConnection();
+
+		$this->expressionBuilder = new ExpressionBuilder($connection);
+
+		$this->doctrineExpressionBuilder = new DoctrineExpressionBuilder($connection);
+	}
+
+	public function dataComparison() {
+		$valueSets = $this->dataComparisons();
+		$comparisonOperators = ['=', '<>', '<', '>', '<=', '>='];
+
+		$testSets = [];
+		foreach ($comparisonOperators as $operator) {
+			foreach ($valueSets as $values) {
+				$testSets[] = array_merge([$operator], $values);
+			}
+		}
+		return $testSets;
+	}
+
+	/**
+	 * @dataProvider dataComparison
+	 *
+	 * @param string $comparison
+	 * @param mixed $input1
+	 * @param bool $isInput1Literal
+	 * @param mixed $input2
+	 * @param bool $isInput2Literal
+	 */
+	public function testComparison($comparison, $input1, $isInput1Literal, $input2, $isInput2Literal) {
+		list($doctrineInput1, $ocInput1) = $this->helpWithLiteral($input1, $isInput1Literal);
+		list($doctrineInput2, $ocInput2) = $this->helpWithLiteral($input2, $isInput2Literal);
+
+		$this->assertEquals(
+			$this->doctrineExpressionBuilder->comparison($doctrineInput1, $comparison, $doctrineInput2),
+			$this->expressionBuilder->comparison($ocInput1, $comparison, $ocInput2)
+		);
+	}
+
+	public function dataComparisons() {
+		return [
+			['value', false, 'value', false],
+			['value', false, 'value', true],
+			['value', true, 'value', false],
+			['value', true, 'value', true],
+		];
+	}
+
+	/**
+	 * @dataProvider dataComparisons
+	 *
+	 * @param mixed $input1
+	 * @param bool $isInput1Literal
+	 * @param mixed $input2
+	 * @param bool $isInput2Literal
+	 */
+	public function testEquals($input1, $isInput1Literal, $input2, $isInput2Literal) {
+		list($doctrineInput1, $ocInput1) = $this->helpWithLiteral($input1, $isInput1Literal);
+		list($doctrineInput2, $ocInput2) = $this->helpWithLiteral($input2, $isInput2Literal);
+
+		$this->assertEquals(
+			$this->doctrineExpressionBuilder->eq($doctrineInput1, $doctrineInput2),
+			$this->expressionBuilder->eq($ocInput1, $ocInput2)
+		);
+	}
+
+	/**
+	 * @dataProvider dataComparisons
+	 *
+	 * @param mixed $input1
+	 * @param bool $isInput1Literal
+	 * @param mixed $input2
+	 * @param bool $isInput2Literal
+	 */
+	public function testNotEquals($input1, $isInput1Literal, $input2, $isInput2Literal) {
+		list($doctrineInput1, $ocInput1) = $this->helpWithLiteral($input1, $isInput1Literal);
+		list($doctrineInput2, $ocInput2) = $this->helpWithLiteral($input2, $isInput2Literal);
+
+		$this->assertEquals(
+			$this->doctrineExpressionBuilder->neq($doctrineInput1, $doctrineInput2),
+			$this->expressionBuilder->neq($ocInput1, $ocInput2)
+		);
+	}
+
+	/**
+	 * @dataProvider dataComparisons
+	 *
+	 * @param mixed $input1
+	 * @param bool $isInput1Literal
+	 * @param mixed $input2
+	 * @param bool $isInput2Literal
+	 */
+	public function testLowerThan($input1, $isInput1Literal, $input2, $isInput2Literal) {
+		list($doctrineInput1, $ocInput1) = $this->helpWithLiteral($input1, $isInput1Literal);
+		list($doctrineInput2, $ocInput2) = $this->helpWithLiteral($input2, $isInput2Literal);
+
+		$this->assertEquals(
+			$this->doctrineExpressionBuilder->lt($doctrineInput1, $doctrineInput2),
+			$this->expressionBuilder->lt($ocInput1, $ocInput2)
+		);
+	}
+
+	/**
+	 * @dataProvider dataComparisons
+	 *
+	 * @param mixed $input1
+	 * @param bool $isInput1Literal
+	 * @param mixed $input2
+	 * @param bool $isInput2Literal
+	 */
+	public function testLowerThanEquals($input1, $isInput1Literal, $input2, $isInput2Literal) {
+		list($doctrineInput1, $ocInput1) = $this->helpWithLiteral($input1, $isInput1Literal);
+		list($doctrineInput2, $ocInput2) = $this->helpWithLiteral($input2, $isInput2Literal);
+
+		$this->assertEquals(
+			$this->doctrineExpressionBuilder->lte($doctrineInput1, $doctrineInput2),
+			$this->expressionBuilder->lte($ocInput1, $ocInput2)
+		);
+	}
+
+	/**
+	 * @dataProvider dataComparisons
+	 *
+	 * @param mixed $input1
+	 * @param bool $isInput1Literal
+	 * @param mixed $input2
+	 * @param bool $isInput2Literal
+	 */
+	public function testGreaterThan($input1, $isInput1Literal, $input2, $isInput2Literal) {
+		list($doctrineInput1, $ocInput1) = $this->helpWithLiteral($input1, $isInput1Literal);
+		list($doctrineInput2, $ocInput2) = $this->helpWithLiteral($input2, $isInput2Literal);
+
+		$this->assertEquals(
+			$this->doctrineExpressionBuilder->gt($doctrineInput1, $doctrineInput2),
+			$this->expressionBuilder->gt($ocInput1, $ocInput2)
+		);
+	}
+
+	/**
+	 * @dataProvider dataComparisons
+	 *
+	 * @param mixed $input1
+	 * @param bool $isInput1Literal
+	 * @param mixed $input2
+	 * @param bool $isInput2Literal
+	 */
+	public function testGreaterThanEquals($input1, $isInput1Literal, $input2, $isInput2Literal) {
+		list($doctrineInput1, $ocInput1) = $this->helpWithLiteral($input1, $isInput1Literal);
+		list($doctrineInput2, $ocInput2) = $this->helpWithLiteral($input2, $isInput2Literal);
+
+		$this->assertEquals(
+			$this->doctrineExpressionBuilder->gte($doctrineInput1, $doctrineInput2),
+			$this->expressionBuilder->gte($ocInput1, $ocInput2)
+		);
+	}
+
+	public function testIsNull() {
+		$this->assertEquals(
+			$this->doctrineExpressionBuilder->isNull('`test`'),
+			$this->expressionBuilder->isNull('test')
+		);
+	}
+
+	public function testIsNotNull() {
+		$this->assertEquals(
+			$this->doctrineExpressionBuilder->isNotNull('`test`'),
+			$this->expressionBuilder->isNotNull('test')
+		);
+	}
+
+	public function dataLike() {
+		return [
+			['value', false],
+			['value', true],
+		];
+	}
+
+	/**
+	 * @dataProvider dataLike
+	 *
+	 * @param mixed $input
+	 * @param bool $isLiteral
+	 */
+	public function testLike($input, $isLiteral) {
+		list($doctrineInput, $ocInput) = $this->helpWithLiteral($input, $isLiteral);
+
+		$this->assertEquals(
+			$this->doctrineExpressionBuilder->like('`test`', $doctrineInput),
+			$this->expressionBuilder->like('test', $ocInput)
+		);
+	}
+
+	/**
+	 * @dataProvider dataLike
+	 *
+	 * @param mixed $input
+	 * @param bool $isLiteral
+	 */
+	public function testNotLike($input, $isLiteral) {
+		list($doctrineInput, $ocInput) = $this->helpWithLiteral($input, $isLiteral);
+
+		$this->assertEquals(
+			$this->doctrineExpressionBuilder->notLike('`test`', $doctrineInput),
+			$this->expressionBuilder->notLike('test', $ocInput)
+		);
+	}
+
+	public function dataIn() {
+		return [
+			['value', false],
+			['value', true],
+			[['value'], false],
+			[['value'], true],
+		];
+	}
+
+	/**
+	 * @dataProvider dataIn
+	 *
+	 * @param mixed $input
+	 * @param bool $isLiteral
+	 */
+	public function testIn($input, $isLiteral) {
+		list($doctrineInput, $ocInput) = $this->helpWithLiteral($input, $isLiteral);
+
+		$this->assertEquals(
+			$this->doctrineExpressionBuilder->in('`test`', $doctrineInput),
+			$this->expressionBuilder->in('test', $ocInput)
+		);
+	}
+
+	/**
+	 * @dataProvider dataIn
+	 *
+	 * @param mixed $input
+	 * @param bool $isLiteral
+	 */
+	public function testNotIn($input, $isLiteral) {
+		list($doctrineInput, $ocInput) = $this->helpWithLiteral($input, $isLiteral);
+
+		$this->assertEquals(
+			$this->doctrineExpressionBuilder->notIn('`test`', $doctrineInput),
+			$this->expressionBuilder->notIn('test', $ocInput)
+		);
+	}
+
+	protected function helpWithLiteral($input, $isLiteral) {
+		if ($isLiteral) {
+			if (is_array($input)) {
+				$doctrineInput = array_map(function ($ident) {
+					return $this->doctrineExpressionBuilder->literal($ident);
+				}, $input);
+				$ocInput = array_map(function ($ident) {
+					return $this->expressionBuilder->literal($ident);
+				}, $input);
+			} else {
+				$doctrineInput = $this->doctrineExpressionBuilder->literal($input);
+				$ocInput = $this->expressionBuilder->literal($input);
+			}
+		} else {
+			if (is_array($input)) {
+				$doctrineInput = array_map(function ($input) {
+					return '`' . $input . '`';
+				}, $input);
+				$ocInput = $input;
+			} else {
+				$doctrineInput = '`' . $input . '`';
+				$ocInput = $input;
+			}
+		}
+
+		return [$doctrineInput, $ocInput];
+	}
+
+	public function dataLiteral() {
+		return [
+			['value', null],
+			['1', null],
+			[1, null],
+			[1, 'string'],
+			[1, 'integer'],
+			[1, \PDO::PARAM_INT],
+		];
+	}
+
+	/**
+	 * @dataProvider dataLiteral
+	 *
+	 * @param mixed $input
+	 * @param string|null $type
+	 */
+	public function testLiteral($input, $type) {
+		/** @var \OC\DB\QueryBuilder\Literal $actual */
+		$actual = $this->expressionBuilder->literal($input, $type);
+
+		$this->assertInstanceOf('\OC\DB\QueryBuilder\Literal', $actual);
+		$this->assertSame(
+			$this->doctrineExpressionBuilder->literal($input, $type),
+			$actual->__toString()
+		);
+	}
+}
diff --git a/tests/lib/db/querybuilder/querybuildertest.php b/tests/lib/db/querybuilder/querybuildertest.php
new file mode 100644
index 0000000000..1b51b9a215
--- /dev/null
+++ b/tests/lib/db/querybuilder/querybuildertest.php
@@ -0,0 +1,941 @@
+<?php
+/**
+ * @author Joas Schilling <nickvergessen@owncloud.com>
+ *
+ * @copyright Copyright (c) 2015, ownCloud, Inc.
+ * @license AGPL-3.0
+ *
+ * This code is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License, version 3,
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>
+ *
+ */
+
+namespace Test\DB\QueryBuilder;
+
+use Doctrine\DBAL\Query\Expression\CompositeExpression;
+use OC\DB\QueryBuilder\Literal;
+use OC\DB\QueryBuilder\Parameter;
+use OC\DB\QueryBuilder\QueryBuilder;
+
+class QueryBuilderTest extends \Test\TestCase {
+	/** @var QueryBuilder */
+	protected $queryBuilder;
+
+	protected function setUp() {
+		parent::setUp();
+
+		$connection = \OC::$server->getDatabaseConnection();
+
+		$this->queryBuilder = new QueryBuilder($connection);
+	}
+
+	public function dataFirstResult() {
+		return [
+			[null, ''],
+			[0, ' OFFSET 0'],
+			[1, ' OFFSET 1'],
+			[5, ' OFFSET 5'],
+		];
+	}
+
+	/**
+	 * @dataProvider dataFirstResult
+	 *
+	 * @param int $firstResult
+	 * @param string $expectedOffset
+	 */
+	public function testFirstResult($firstResult, $expectedOffset) {
+		if ($firstResult !== null) {
+			$this->queryBuilder->setFirstResult($firstResult);
+		}
+
+		$this->assertSame(
+			$firstResult,
+			$this->queryBuilder->getFirstResult()
+		);
+
+		$this->assertSame(
+			'SELECT  FROM ' . $expectedOffset,
+			$this->queryBuilder->getSQL()
+		);
+	}
+
+	public function dataMaxResults() {
+		return [
+			[null, ''],
+			[0, ' LIMIT 0'],
+			[1, ' LIMIT 1'],
+			[5, ' LIMIT 5'],
+		];
+	}
+
+	/**
+	 * @dataProvider dataMaxResults
+	 *
+	 * @param int $maxResult
+	 * @param string $expectedLimit
+	 */
+	public function testMaxResults($maxResult, $expectedLimit) {
+		if ($maxResult !== null) {
+			$this->queryBuilder->setMaxResults($maxResult);
+		}
+
+		$this->assertSame(
+			$maxResult,
+			$this->queryBuilder->getMaxResults()
+		);
+
+		$this->assertSame(
+			'SELECT  FROM ' . $expectedLimit,
+			$this->queryBuilder->getSQL()
+		);
+	}
+
+	public function dataSelect() {
+		return [
+			// select('column1')
+			[['column1'], ['`column1`'], '`column1`'],
+
+			// select('column1', 'column2')
+			[['column1', 'column2'], ['`column1`', '`column2`'], '`column1`, `column2`'],
+
+			// select(['column1', 'column2'])
+			[[['column1', 'column2']], ['`column1`', '`column2`'], '`column1`, `column2`'],
+
+			// select(new Literal('column1'))
+			[[new Literal('column1')], ['column1'], 'column1'],
+
+			// select('column1', 'column2')
+			[[new Literal('column1'), 'column2'], ['column1', '`column2`'], 'column1, `column2`'],
+
+			// select(['column1', 'column2'])
+			[[[new Literal('column1'), 'column2']], ['column1', '`column2`'], 'column1, `column2`'],
+		];
+	}
+
+	/**
+	 * @dataProvider dataSelect
+	 *
+	 * @param array $selectArguments
+	 * @param array $expectedQueryPart
+	 * @param string $expectedSelect
+	 */
+	public function testSelect($selectArguments, $expectedQueryPart, $expectedSelect) {
+		call_user_func_array(
+			[$this->queryBuilder, 'select'],
+			$selectArguments
+		);
+
+		$this->assertSame(
+			$expectedQueryPart,
+			$this->queryBuilder->getQueryPart('select')
+		);
+
+		$this->assertSame(
+			'SELECT ' . $expectedSelect . ' FROM ',
+			$this->queryBuilder->getSQL()
+		);
+	}
+
+	public function dataAddSelect() {
+		return [
+			// addSelect('column1')
+			[['column1'], ['`column`', '`column1`'], '`column`, `column1`'],
+
+			// addSelect('column1', 'column2')
+			[['column1', 'column2'], ['`column`', '`column1`', '`column2`'], '`column`, `column1`, `column2`'],
+
+			// addSelect(['column1', 'column2'])
+			[[['column1', 'column2']], ['`column`', '`column1`', '`column2`'], '`column`, `column1`, `column2`'],
+
+			// select(new Literal('column1'))
+			[[new Literal('column1')], ['`column`', 'column1'], '`column`, column1'],
+
+			// select('column1', 'column2')
+			[[new Literal('column1'), 'column2'], ['`column`', 'column1', '`column2`'], '`column`, column1, `column2`'],
+
+			// select(['column1', 'column2'])
+			[[[new Literal('column1'), 'column2']], ['`column`', 'column1', '`column2`'], '`column`, column1, `column2`'],
+		];
+	}
+
+	/**
+	 * @dataProvider dataAddSelect
+	 *
+	 * @param array $selectArguments
+	 * @param array $expectedQueryPart
+	 * @param string $expectedSelect
+	 */
+	public function testAddSelect($selectArguments, $expectedQueryPart, $expectedSelect) {
+		$this->queryBuilder->select('column');
+		call_user_func_array(
+			[$this->queryBuilder, 'addSelect'],
+			$selectArguments
+		);
+
+		$this->assertSame(
+			$expectedQueryPart,
+			$this->queryBuilder->getQueryPart('select')
+		);
+
+		$this->assertSame(
+			'SELECT ' . $expectedSelect . ' FROM ',
+			$this->queryBuilder->getSQL()
+		);
+	}
+
+	public function dataDelete() {
+		return [
+			['data', null, ['table' => '`data`', 'alias' => null], '`data`'],
+			['data', 't', ['table' => '`data`', 'alias' => 't'], '`data` t'],
+		];
+	}
+
+	/**
+	 * @dataProvider dataDelete
+	 *
+	 * @param string $tableName
+	 * @param string $tableAlias
+	 * @param array $expectedQueryPart
+	 * @param string $expectedQuery
+	 */
+	public function testDelete($tableName, $tableAlias, $expectedQueryPart, $expectedQuery) {
+		$this->queryBuilder->delete($tableName, $tableAlias);
+
+		$this->assertSame(
+			$expectedQueryPart,
+			$this->queryBuilder->getQueryPart('from')
+		);
+
+		$this->assertSame(
+			'DELETE FROM ' . $expectedQuery,
+			$this->queryBuilder->getSQL()
+		);
+	}
+
+	public function dataUpdate() {
+		return [
+			['data', null, ['table' => '`data`', 'alias' => null], '`data`'],
+			['data', 't', ['table' => '`data`', 'alias' => 't'], '`data` t'],
+		];
+	}
+
+	/**
+	 * @dataProvider dataUpdate
+	 *
+	 * @param string $tableName
+	 * @param string $tableAlias
+	 * @param array $expectedQueryPart
+	 * @param string $expectedQuery
+	 */
+	public function testUpdate($tableName, $tableAlias, $expectedQueryPart, $expectedQuery) {
+		$this->queryBuilder->update($tableName, $tableAlias);
+
+		$this->assertSame(
+			$expectedQueryPart,
+			$this->queryBuilder->getQueryPart('from')
+		);
+
+		$this->assertSame(
+			'UPDATE ' . $expectedQuery . ' SET ',
+			$this->queryBuilder->getSQL()
+		);
+	}
+
+	public function dataInsert() {
+		return [
+			['data', ['table' => '`data`'], '`data`'],
+		];
+	}
+
+	/**
+	 * @dataProvider dataInsert
+	 *
+	 * @param string $tableName
+	 * @param array $expectedQueryPart
+	 * @param string $expectedQuery
+	 */
+	public function testInsert($tableName, $expectedQueryPart, $expectedQuery) {
+		$this->queryBuilder->insert($tableName);
+
+		$this->assertSame(
+			$expectedQueryPart,
+			$this->queryBuilder->getQueryPart('from')
+		);
+
+		$this->assertSame(
+			'INSERT INTO ' . $expectedQuery . ' () VALUES()',
+			$this->queryBuilder->getSQL()
+		);
+	}
+
+	public function dataFrom() {
+		return [
+			['data', null, null, null, [['table' => '`data`', 'alias' => null]], '`data`'],
+			['data', 't', null, null, [['table' => '`data`', 'alias' => 't']], '`data` t'],
+			['data1', null, 'data2', null, [
+				['table' => '`data1`', 'alias' => null],
+				['table' => '`data2`', 'alias' => null]
+			], '`data1`, `data2`'],
+			['data', 't1', 'data', 't2', [
+				['table' => '`data`', 'alias' => 't1'],
+				['table' => '`data`', 'alias' => 't2']
+			], '`data` t1, `data` t2'],
+		];
+	}
+
+	/**
+	 * @dataProvider dataFrom
+	 *
+	 * @param string $table1Name
+	 * @param string $table1Alias
+	 * @param string $table2Name
+	 * @param string $table2Alias
+	 * @param array $expectedQueryPart
+	 * @param string $expectedQuery
+	 */
+	public function testFrom($table1Name, $table1Alias, $table2Name, $table2Alias, $expectedQueryPart, $expectedQuery) {
+		$this->queryBuilder->from($table1Name, $table1Alias);
+		if ($table2Name !== null) {
+			$this->queryBuilder->from($table2Name, $table2Alias);
+		}
+
+		$this->assertSame(
+			$expectedQueryPart,
+			$this->queryBuilder->getQueryPart('from')
+		);
+
+		$this->assertSame(
+			'SELECT  FROM ' . $expectedQuery,
+			$this->queryBuilder->getSQL()
+		);
+	}
+
+	public function dataJoin() {
+		return [
+			[
+				'd1', 'data2', null, null,
+				['d1' => [['joinType' => 'inner', 'joinTable' => '`data2`', 'joinAlias' => null, 'joinCondition' => null]]],
+				'`data1` d1 INNER JOIN `data2`  ON '
+			],
+			[
+				'd1', 'data2', 'd2', null,
+				['d1' => [['joinType' => 'inner', 'joinTable' => '`data2`', 'joinAlias' => 'd2', 'joinCondition' => null]]],
+				'`data1` d1 INNER JOIN `data2` d2 ON '
+			],
+			[
+				'd1', 'data2', 'd2', 'd1.`field1` = d2.`field2`',
+				['d1' => [['joinType' => 'inner', 'joinTable' => '`data2`', 'joinAlias' => 'd2', 'joinCondition' => 'd1.`field1` = d2.`field2`']]],
+				'`data1` d1 INNER JOIN `data2` d2 ON d1.`field1` = d2.`field2`'
+			],
+
+		];
+	}
+
+	/**
+	 * @dataProvider dataJoin
+	 *
+	 * @param string $fromAlias
+	 * @param string $tableName
+	 * @param string $tableAlias
+	 * @param string $condition
+	 * @param array $expectedQueryPart
+	 * @param string $expectedQuery
+	 */
+	public function testJoin($fromAlias, $tableName, $tableAlias, $condition, $expectedQueryPart, $expectedQuery) {
+		$this->queryBuilder->from('data1', 'd1');
+		$this->queryBuilder->join(
+			$fromAlias,
+			$tableName,
+			$tableAlias,
+			$condition
+		);
+
+		$this->assertSame(
+			$expectedQueryPart,
+			$this->queryBuilder->getQueryPart('join')
+		);
+
+		$this->assertSame(
+			'SELECT  FROM ' . $expectedQuery,
+			$this->queryBuilder->getSQL()
+		);
+	}
+
+	/**
+	 * @dataProvider dataJoin
+	 *
+	 * @param string $fromAlias
+	 * @param string $tableName
+	 * @param string $tableAlias
+	 * @param string $condition
+	 * @param array $expectedQueryPart
+	 * @param string $expectedQuery
+	 */
+	public function testInnerJoin($fromAlias, $tableName, $tableAlias, $condition, $expectedQueryPart, $expectedQuery) {
+		$this->queryBuilder->from('data1', 'd1');
+		$this->queryBuilder->innerJoin(
+			$fromAlias,
+			$tableName,
+			$tableAlias,
+			$condition
+		);
+
+		$this->assertSame(
+			$expectedQueryPart,
+			$this->queryBuilder->getQueryPart('join')
+		);
+
+		$this->assertSame(
+			'SELECT  FROM ' . $expectedQuery,
+			$this->queryBuilder->getSQL()
+		);
+	}
+
+	public function dataLeftJoin() {
+		return [
+			[
+				'd1', 'data2', null, null,
+				['d1' => [['joinType' => 'left', 'joinTable' => '`data2`', 'joinAlias' => null, 'joinCondition' => null]]],
+				'`data1` d1 LEFT JOIN `data2`  ON '
+			],
+			[
+				'd1', 'data2', 'd2', null,
+				['d1' => [['joinType' => 'left', 'joinTable' => '`data2`', 'joinAlias' => 'd2', 'joinCondition' => null]]],
+				'`data1` d1 LEFT JOIN `data2` d2 ON '
+			],
+			[
+				'd1', 'data2', 'd2', 'd1.`field1` = d2.`field2`',
+				['d1' => [['joinType' => 'left', 'joinTable' => '`data2`', 'joinAlias' => 'd2', 'joinCondition' => 'd1.`field1` = d2.`field2`']]],
+				'`data1` d1 LEFT JOIN `data2` d2 ON d1.`field1` = d2.`field2`'
+			],
+		];
+	}
+
+	/**
+	 * @dataProvider dataLeftJoin
+	 *
+	 * @param string $fromAlias
+	 * @param string $tableName
+	 * @param string $tableAlias
+	 * @param string $condition
+	 * @param array $expectedQueryPart
+	 * @param string $expectedQuery
+	 */
+	public function testLeftJoin($fromAlias, $tableName, $tableAlias, $condition, $expectedQueryPart, $expectedQuery) {
+		$this->queryBuilder->from('data1', 'd1');
+		$this->queryBuilder->leftJoin(
+			$fromAlias,
+			$tableName,
+			$tableAlias,
+			$condition
+		);
+
+		$this->assertSame(
+			$expectedQueryPart,
+			$this->queryBuilder->getQueryPart('join')
+		);
+
+		$this->assertSame(
+			'SELECT  FROM ' . $expectedQuery,
+			$this->queryBuilder->getSQL()
+		);
+	}
+
+	public function dataRightJoin() {
+		return [
+			[
+				'd1', 'data2', null, null,
+				['d1' => [['joinType' => 'right', 'joinTable' => '`data2`', 'joinAlias' => null, 'joinCondition' => null]]],
+				'`data1` d1 RIGHT JOIN `data2`  ON '
+			],
+			[
+				'd1', 'data2', 'd2', null,
+				['d1' => [['joinType' => 'right', 'joinTable' => '`data2`', 'joinAlias' => 'd2', 'joinCondition' => null]]],
+				'`data1` d1 RIGHT JOIN `data2` d2 ON '
+			],
+			[
+				'd1', 'data2', 'd2', 'd1.`field1` = d2.`field2`',
+				['d1' => [['joinType' => 'right', 'joinTable' => '`data2`', 'joinAlias' => 'd2', 'joinCondition' => 'd1.`field1` = d2.`field2`']]],
+				'`data1` d1 RIGHT JOIN `data2` d2 ON d1.`field1` = d2.`field2`'
+			],
+		];
+	}
+
+	/**
+	 * @dataProvider dataRightJoin
+	 *
+	 * @param string $fromAlias
+	 * @param string $tableName
+	 * @param string $tableAlias
+	 * @param string $condition
+	 * @param array $expectedQueryPart
+	 * @param string $expectedQuery
+	 */
+	public function testRightJoin($fromAlias, $tableName, $tableAlias, $condition, $expectedQueryPart, $expectedQuery) {
+		$this->queryBuilder->from('data1', 'd1');
+		$this->queryBuilder->rightJoin(
+			$fromAlias,
+			$tableName,
+			$tableAlias,
+			$condition
+		);
+
+		$this->assertSame(
+			$expectedQueryPart,
+			$this->queryBuilder->getQueryPart('join')
+		);
+
+		$this->assertSame(
+			'SELECT  FROM ' . $expectedQuery,
+			$this->queryBuilder->getSQL()
+		);
+	}
+
+	public function dataSet() {
+		return [
+			['column1', new Literal('value'), null, null, ['`column1` = value'], '`column1` = value'],
+			['column1', new Parameter(':param'), null, null, ['`column1` = :param'], '`column1` = :param'],
+			['column1', 'column2', null, null, ['`column1` = `column2`'], '`column1` = `column2`'],
+			['column1', 'column2', 'column3', new Literal('value'), ['`column1` = `column2`', '`column3` = value'], '`column1` = `column2`, `column3` = value'],
+		];
+	}
+
+	/**
+	 * @dataProvider dataSet
+	 *
+	 * @param string $partOne1
+	 * @param string $partOne2
+	 * @param string $partTwo1
+	 * @param string $partTwo2
+	 * @param array $expectedQueryPart
+	 * @param string $expectedQuery
+	 */
+	public function testSet($partOne1, $partOne2, $partTwo1, $partTwo2, $expectedQueryPart, $expectedQuery) {
+		$this->queryBuilder->update('data');
+		$this->queryBuilder->set($partOne1, $partOne2);
+		if ($partTwo1 !== null) {
+			$this->queryBuilder->set($partTwo1, $partTwo2);
+		}
+
+		$this->assertSame(
+			$expectedQueryPart,
+			$this->queryBuilder->getQueryPart('set')
+		);
+
+		$this->assertSame(
+			'UPDATE `data` SET ' . $expectedQuery,
+			$this->queryBuilder->getSQL()
+		);
+	}
+
+	public function dataWhere() {
+		return [
+			[['where1'], new CompositeExpression('AND', ['where1']), 'where1'],
+			[['where1', 'where2'], new CompositeExpression('AND', ['where1', 'where2']), '(where1) AND (where2)'],
+		];
+	}
+
+	/**
+	 * @dataProvider dataWhere
+	 *
+	 * @param array $whereArguments
+	 * @param array $expectedQueryPart
+	 * @param string $expectedQuery
+	 */
+	public function testWhere($whereArguments, $expectedQueryPart, $expectedQuery) {
+		$this->queryBuilder->select('column');
+		call_user_func_array(
+			[$this->queryBuilder, 'where'],
+			$whereArguments
+		);
+
+		$this->assertEquals(
+			$expectedQueryPart,
+			$this->queryBuilder->getQueryPart('where')
+		);
+
+		$this->assertSame(
+			'SELECT `column` FROM  WHERE ' . $expectedQuery,
+			$this->queryBuilder->getSQL()
+		);
+	}
+
+	/**
+	 * @dataProvider dataWhere
+	 *
+	 * @param array $whereArguments
+	 * @param array $expectedQueryPart
+	 * @param string $expectedQuery
+	 */
+	public function testAndWhere($whereArguments, $expectedQueryPart, $expectedQuery) {
+		$this->queryBuilder->select('column');
+		call_user_func_array(
+			[$this->queryBuilder, 'andWhere'],
+			$whereArguments
+		);
+
+		$this->assertEquals(
+			$expectedQueryPart,
+			$this->queryBuilder->getQueryPart('where')
+		);
+
+		$this->assertSame(
+			'SELECT `column` FROM  WHERE ' . $expectedQuery,
+			$this->queryBuilder->getSQL()
+		);
+	}
+
+	public function dataOrWhere() {
+		return [
+			[['where1'], new CompositeExpression('OR', ['where1']), 'where1'],
+			[['where1', 'where2'], new CompositeExpression('OR', ['where1', 'where2']), '(where1) OR (where2)'],
+		];
+	}
+
+	/**
+	 * @dataProvider dataOrWhere
+	 *
+	 * @param array $whereArguments
+	 * @param array $expectedQueryPart
+	 * @param string $expectedQuery
+	 */
+	public function testOrWhere($whereArguments, $expectedQueryPart, $expectedQuery) {
+		$this->queryBuilder->select('column');
+		call_user_func_array(
+			[$this->queryBuilder, 'orWhere'],
+			$whereArguments
+		);
+
+		$this->assertEquals(
+			$expectedQueryPart,
+			$this->queryBuilder->getQueryPart('where')
+		);
+
+		$this->assertSame(
+			'SELECT `column` FROM  WHERE ' . $expectedQuery,
+			$this->queryBuilder->getSQL()
+		);
+	}
+
+	public function dataGroupBy() {
+		return [
+			[['column1'], ['`column1`'], '`column1`'],
+			[['column1', 'column2'], ['`column1`', '`column2`'], '`column1`, `column2`'],
+		];
+	}
+
+	/**
+	 * @dataProvider dataGroupBy
+	 *
+	 * @param array $groupByArguments
+	 * @param array $expectedQueryPart
+	 * @param string $expectedQuery
+	 */
+	public function testGroupBy($groupByArguments, $expectedQueryPart, $expectedQuery) {
+		$this->queryBuilder->select('column');
+		call_user_func_array(
+			[$this->queryBuilder, 'groupBy'],
+			$groupByArguments
+		);
+
+		$this->assertEquals(
+			$expectedQueryPart,
+			$this->queryBuilder->getQueryPart('groupBy')
+		);
+
+		$this->assertSame(
+			'SELECT `column` FROM  GROUP BY ' . $expectedQuery,
+			$this->queryBuilder->getSQL()
+		);
+	}
+
+	public function dataAddGroupBy() {
+		return [
+			[['column2'], ['`column1`', '`column2`'], '`column1`, `column2`'],
+			[['column2', 'column3'], ['`column1`', '`column2`', '`column3`'], '`column1`, `column2`, `column3`'],
+		];
+	}
+
+	/**
+	 * @dataProvider dataAddGroupBy
+	 *
+	 * @param array $groupByArguments
+	 * @param array $expectedQueryPart
+	 * @param string $expectedQuery
+	 */
+	public function testAddGroupBy($groupByArguments, $expectedQueryPart, $expectedQuery) {
+		$this->queryBuilder->select('column');
+		$this->queryBuilder->groupBy('column1');
+		call_user_func_array(
+			[$this->queryBuilder, 'addGroupBy'],
+			$groupByArguments
+		);
+
+		$this->assertEquals(
+			$expectedQueryPart,
+			$this->queryBuilder->getQueryPart('groupBy')
+		);
+
+		$this->assertSame(
+			'SELECT `column` FROM  GROUP BY ' . $expectedQuery,
+			$this->queryBuilder->getSQL()
+		);
+	}
+
+	public function dataSetValue() {
+		return [
+			['column', 'value', ['`column`' => 'value'], '(`column`) VALUES(value)'],
+		];
+	}
+
+	/**
+	 * @dataProvider dataSetValue
+	 *
+	 * @param string $column
+	 * @param string $value
+	 * @param array $expectedQueryPart
+	 * @param string $expectedQuery
+	 */
+	public function testSetValue($column, $value, $expectedQueryPart, $expectedQuery) {
+		$this->queryBuilder->insert('data');
+		$this->queryBuilder->setValue($column, $value);
+
+		$this->assertEquals(
+			$expectedQueryPart,
+			$this->queryBuilder->getQueryPart('values')
+		);
+
+		$this->assertSame(
+			'INSERT INTO `data` ' . $expectedQuery,
+			$this->queryBuilder->getSQL()
+		);
+	}
+
+	/**
+	 * @dataProvider dataSetValue
+	 *
+	 * @param string $column
+	 * @param string $value
+	 * @param array $expectedQueryPart
+	 * @param string $expectedQuery
+	 */
+	public function testValues($column, $value, $expectedQueryPart, $expectedQuery) {
+		$this->queryBuilder->insert('data');
+		$this->queryBuilder->values([
+			$column => $value,
+		]);
+
+		$this->assertEquals(
+			$expectedQueryPart,
+			$this->queryBuilder->getQueryPart('values')
+		);
+
+		$this->assertSame(
+			'INSERT INTO `data` ' . $expectedQuery,
+			$this->queryBuilder->getSQL()
+		);
+	}
+
+	public function dataHaving() {
+		return [
+			[['condition1'], new CompositeExpression('AND', ['condition1']), 'HAVING condition1'],
+			[['condition1', 'condition2'], new CompositeExpression('AND', ['condition1', 'condition2']), 'HAVING (condition1) AND (condition2)'],
+			[
+				[new CompositeExpression('OR', ['condition1', 'condition2'])],
+				new CompositeExpression('OR', ['condition1', 'condition2']),
+				'HAVING (condition1) OR (condition2)'
+			],
+			[
+				[new CompositeExpression('AND', ['condition1', 'condition2'])],
+				new CompositeExpression('AND', ['condition1', 'condition2']),
+				'HAVING (condition1) AND (condition2)'
+			],
+		];
+	}
+
+	/**
+	 * @dataProvider dataHaving
+	 *
+	 * @param array $havingArguments
+	 * @param array $expectedQueryPart
+	 * @param string $expectedQuery
+	 */
+	public function testHaving($havingArguments, $expectedQueryPart, $expectedQuery) {
+		call_user_func_array(
+			[$this->queryBuilder, 'having'],
+			$havingArguments
+		);
+
+		$this->assertEquals(
+			$expectedQueryPart,
+			$this->queryBuilder->getQueryPart('having')
+		);
+
+		$this->assertSame(
+			'SELECT  FROM  ' . $expectedQuery,
+			$this->queryBuilder->getSQL()
+		);
+	}
+
+	public function dataAndHaving() {
+		return [
+			[['condition2'], new CompositeExpression('AND', ['condition1', 'condition2']), 'HAVING (condition1) AND (condition2)'],
+			[['condition2', 'condition3'], new CompositeExpression('AND', ['condition1', 'condition2', 'condition3']), 'HAVING (condition1) AND (condition2) AND (condition3)'],
+			[
+				[new CompositeExpression('OR', ['condition2', 'condition3'])],
+				new CompositeExpression('AND', ['condition1', new CompositeExpression('OR', ['condition2', 'condition3'])]),
+				'HAVING (condition1) AND ((condition2) OR (condition3))'
+			],
+			[
+				[new CompositeExpression('AND', ['condition2', 'condition3'])],
+				new CompositeExpression('AND', ['condition1', new CompositeExpression('AND', ['condition2', 'condition3'])]),
+				'HAVING (condition1) AND ((condition2) AND (condition3))'
+			],
+		];
+	}
+
+	/**
+	 * @dataProvider dataAndHaving
+	 *
+	 * @param array $havingArguments
+	 * @param array $expectedQueryPart
+	 * @param string $expectedQuery
+	 */
+	public function testAndHaving($havingArguments, $expectedQueryPart, $expectedQuery) {
+		$this->queryBuilder->having('condition1');
+		call_user_func_array(
+			[$this->queryBuilder, 'andHaving'],
+			$havingArguments
+		);
+
+		$this->assertEquals(
+			$expectedQueryPart,
+			$this->queryBuilder->getQueryPart('having')
+		);
+
+		$this->assertSame(
+			'SELECT  FROM  ' . $expectedQuery,
+			$this->queryBuilder->getSQL()
+		);
+	}
+
+	public function dataOrHaving() {
+		return [
+			[['condition2'], new CompositeExpression('OR', ['condition1', 'condition2']), 'HAVING (condition1) OR (condition2)'],
+			[['condition2', 'condition3'], new CompositeExpression('OR', ['condition1', 'condition2', 'condition3']), 'HAVING (condition1) OR (condition2) OR (condition3)'],
+			[
+				[new CompositeExpression('OR', ['condition2', 'condition3'])],
+				new CompositeExpression('OR', ['condition1', new CompositeExpression('OR', ['condition2', 'condition3'])]),
+				'HAVING (condition1) OR ((condition2) OR (condition3))'
+			],
+			[
+				[new CompositeExpression('AND', ['condition2', 'condition3'])],
+				new CompositeExpression('OR', ['condition1', new CompositeExpression('AND', ['condition2', 'condition3'])]),
+				'HAVING (condition1) OR ((condition2) AND (condition3))'
+			],
+		];
+	}
+
+	/**
+	 * @dataProvider dataOrHaving
+	 *
+	 * @param array $havingArguments
+	 * @param array $expectedQueryPart
+	 * @param string $expectedQuery
+	 */
+	public function testOrHaving($havingArguments, $expectedQueryPart, $expectedQuery) {
+		$this->queryBuilder->having('condition1');
+		call_user_func_array(
+			[$this->queryBuilder, 'orHaving'],
+			$havingArguments
+		);
+
+		$this->assertEquals(
+			$expectedQueryPart,
+			$this->queryBuilder->getQueryPart('having')
+		);
+
+		$this->assertSame(
+			'SELECT  FROM  ' . $expectedQuery,
+			$this->queryBuilder->getSQL()
+		);
+	}
+
+	public function dataOrderBy() {
+		return [
+			['column', null, ['`column` ASC'], 'ORDER BY `column` ASC'],
+			['column', 'ASC', ['`column` ASC'], 'ORDER BY `column` ASC'],
+			['column', 'DESC', ['`column` DESC'], 'ORDER BY `column` DESC'],
+		];
+	}
+
+	/**
+	 * @dataProvider dataOrderBy
+	 *
+	 * @param string $sort
+	 * @param string $order
+	 * @param array $expectedQueryPart
+	 * @param string $expectedQuery
+	 */
+	public function testOrderBy($sort, $order, $expectedQueryPart, $expectedQuery) {
+		$this->queryBuilder->orderBy($sort, $order);
+
+		$this->assertEquals(
+			$expectedQueryPart,
+			$this->queryBuilder->getQueryPart('orderBy')
+		);
+
+		$this->assertSame(
+			'SELECT  FROM  ' . $expectedQuery,
+			$this->queryBuilder->getSQL()
+		);
+	}
+
+	public function dataAddOrderBy() {
+		return [
+			['column2', null, null, ['`column1` ASC', '`column2` ASC'], 'ORDER BY `column1` ASC, `column2` ASC'],
+			['column2', null, 'ASC', ['`column1` ASC', '`column2` ASC'], 'ORDER BY `column1` ASC, `column2` ASC'],
+			['column2', null, 'DESC', ['`column1` DESC', '`column2` ASC'], 'ORDER BY `column1` DESC, `column2` ASC'],
+			['column2', 'ASC', null, ['`column1` ASC', '`column2` ASC'], 'ORDER BY `column1` ASC, `column2` ASC'],
+			['column2', 'ASC', 'ASC', ['`column1` ASC', '`column2` ASC'], 'ORDER BY `column1` ASC, `column2` ASC'],
+			['column2', 'ASC', 'DESC', ['`column1` DESC', '`column2` ASC'], 'ORDER BY `column1` DESC, `column2` ASC'],
+			['column2', 'DESC', null, ['`column1` ASC', '`column2` DESC'], 'ORDER BY `column1` ASC, `column2` DESC'],
+			['column2', 'DESC', 'ASC', ['`column1` ASC', '`column2` DESC'], 'ORDER BY `column1` ASC, `column2` DESC'],
+			['column2', 'DESC', 'DESC', ['`column1` DESC', '`column2` DESC'], 'ORDER BY `column1` DESC, `column2` DESC'],
+		];
+	}
+
+	/**
+	 * @dataProvider dataAddOrderBy
+	 *
+	 * @param string $sort2
+	 * @param string $order2
+	 * @param string $order1
+	 * @param array $expectedQueryPart
+	 * @param string $expectedQuery
+	 */
+	public function testAddOrderBy($sort2, $order2, $order1, $expectedQueryPart, $expectedQuery) {
+		$this->queryBuilder->orderBy('column1', $order1);
+		$this->queryBuilder->addOrderBy($sort2, $order2);
+
+		$this->assertEquals(
+			$expectedQueryPart,
+			$this->queryBuilder->getQueryPart('orderBy')
+		);
+
+		$this->assertSame(
+			'SELECT  FROM  ' . $expectedQuery,
+			$this->queryBuilder->getSQL()
+		);
+	}
+}
diff --git a/tests/lib/db/querybuilder/quotehelpertest.php b/tests/lib/db/querybuilder/quotehelpertest.php
new file mode 100644
index 0000000000..904b4c500d
--- /dev/null
+++ b/tests/lib/db/querybuilder/quotehelpertest.php
@@ -0,0 +1,141 @@
+<?php
+/**
+ * @author Joas Schilling <nickvergessen@owncloud.com>
+ *
+ * @copyright Copyright (c) 2015, ownCloud, Inc.
+ * @license AGPL-3.0
+ *
+ * This code is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License, version 3,
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>
+ *
+ */
+
+namespace Test\DB\QueryBuilder;
+
+use OC\DB\QueryBuilder\Literal;
+use OC\DB\QueryBuilder\Parameter;
+use OC\DB\QueryBuilder\QuoteHelper;
+use OCP\DB\QueryBuilder\ILiteral;
+use OCP\DB\QueryBuilder\IParameter;
+
+class QuoteHelperTest extends \Test\TestCase {
+	/** @var QuoteHelper */
+	protected $helper;
+
+	protected function setUp() {
+		parent::setUp();
+
+		$this->helper = new QuoteHelper();
+	}
+
+	public function dataQuoteColumnName() {
+		return [
+			['column', '`column`'],
+			[new Literal('literal'), 'literal'],
+			[new Literal(1), '1'],
+			[new Parameter(':param'), ':param'],
+		];
+	}
+
+	/**
+	 * @dataProvider dataQuoteColumnName
+	 * @param mixed $input
+	 * @param string $expected
+	 */
+	public function testQuoteColumnName($input, $expected) {
+		$this->assertSame(
+			$expected,
+			$this->helper->quoteColumnName($input)
+		);
+	}
+
+	public function dataQuoteColumnNames() {
+		return [
+			// Single case
+			['d.column', 'd.`column`'],
+			['column', '`column`'],
+			[new Literal('literal'), 'literal'],
+			[new Literal(1), '1'],
+			[new Parameter(':param'), ':param'],
+
+			// Array case
+			[['column'], ['`column`']],
+			[[new Literal('literal')], ['literal']],
+			[[new Literal(1)], ['1']],
+			[[new Parameter(':param')], [':param']],
+
+			// Array mixed cases
+			[['column1', 'column2'], ['`column1`', '`column2`']],
+			[['column', new Literal('literal')], ['`column`', 'literal']],
+			[['column', new Literal(1)], ['`column`', '1']],
+			[['column', new Parameter(':param')], ['`column`', ':param']],
+		];
+	}
+
+	/**
+	 * @dataProvider dataQuoteColumnNames
+	 * @param mixed $input
+	 * @param string $expected
+	 */
+	public function testQuoteColumnNames($input, $expected) {
+		$this->assertSame(
+			$expected,
+			$this->helper->quoteColumnNames($input)
+		);
+	}
+
+	/**
+	 * @param array|string|ILiteral|IParameter $strings string, Literal or Parameter
+	 * @return array|string
+	 */
+	public function quoteColumnNames($strings) {
+		if (!is_array($strings)) {
+			return $this->quoteColumnName($strings);
+		}
+
+		$return = [];
+		foreach ($strings as $string) {
+			$return[] = $this->quoteColumnName($string);
+		}
+
+		return $return;
+	}
+
+	/**
+	 * @param string|ILiteral|IParameter $string string, Literal or Parameter
+	 * @return string
+	 */
+	public function quoteColumnName($string) {
+		if ($string instanceof IParameter) {
+			return $string->getName();
+		}
+
+		if ($string instanceof ILiteral) {
+			return $string->getLiteral();
+		}
+
+		if ($string === null) {
+			return $string;
+		}
+
+		if (!is_string($string)) {
+			throw new \InvalidArgumentException('Only strings, Literals and Parameters are allowed');
+		}
+
+		if (substr_count($string, '.')) {
+			list($alias, $columnName) = explode('.', $string);
+			return '`' . $alias . '`.`' . $columnName . '`';
+		}
+
+		return '`' . $string . '`';
+	}
+}
diff --git a/tests/lib/share/share.php b/tests/lib/share/share.php
index e57dd43f83..816070afd8 100644
--- a/tests/lib/share/share.php
+++ b/tests/lib/share/share.php
@@ -1335,10 +1335,10 @@ class Test_Share extends \Test\TestCase {
 		$userSession->method('getUser')->willReturn($user);
 
 
-		$ex = $this->getMockBuilder('\OC\DB\ExpressionBuilder')
+		$ex = $this->getMockBuilder('\OC\DB\QueryBuilder\ExpressionBuilder')
 		           ->disableOriginalConstructor()
 		           ->getMock();
-		$qb = $this->getMockBuilder('\OC\DB\QueryBuilder')
+		$qb = $this->getMockBuilder('\OC\DB\QueryBuilder\QueryBuilder')
 		           ->disableOriginalConstructor()
 		           ->getMock();
 		$qb->method('update')->will($this->returnSelf());
@@ -1390,10 +1390,10 @@ class Test_Share extends \Test\TestCase {
 		$userSession->method('getUser')->willReturn($user);
 
 
-		$ex = $this->getMockBuilder('\OC\DB\ExpressionBuilder')
+		$ex = $this->getMockBuilder('\OC\DB\QueryBuilder\ExpressionBuilder')
 		           ->disableOriginalConstructor()
 		           ->getMock();
-		$qb = $this->getMockBuilder('\OC\DB\QueryBuilder')
+		$qb = $this->getMockBuilder('\OC\DB\QueryBuilder\QueryBuilder')
 		           ->disableOriginalConstructor()
 		           ->getMock();
 		$qb->method('update')->will($this->returnSelf());
@@ -1443,10 +1443,10 @@ class Test_Share extends \Test\TestCase {
 		$userSession->method('getUser')->willReturn($user);
 
 
-		$ex = $this->getMockBuilder('\OC\DB\ExpressionBuilder')
+		$ex = $this->getMockBuilder('\OC\DB\QueryBuilder\ExpressionBuilder')
 		           ->disableOriginalConstructor()
 		           ->getMock();
-		$qb = $this->getMockBuilder('\OC\DB\QueryBuilder')
+		$qb = $this->getMockBuilder('\OC\DB\QueryBuilder\QueryBuilder')
 		           ->disableOriginalConstructor()
 		           ->getMock();
 		$qb->method('update')->will($this->returnSelf());
@@ -1496,10 +1496,10 @@ class Test_Share extends \Test\TestCase {
 		$userSession->method('getUser')->willReturn($user);
 
 
-		$ex = $this->getMockBuilder('\OC\DB\ExpressionBuilder')
+		$ex = $this->getMockBuilder('\OC\DB\QueryBuilder\ExpressionBuilder')
 		           ->disableOriginalConstructor()
 		           ->getMock();
-		$qb = $this->getMockBuilder('\OC\DB\QueryBuilder')
+		$qb = $this->getMockBuilder('\OC\DB\QueryBuilder\QueryBuilder')
 		           ->disableOriginalConstructor()
 		           ->getMock();
 		$qb->method('update')->will($this->returnSelf());