nextcloud/lib/private/db/adapter.php

<?php
/**
 * Copyright (c) 2013 Bart Visscher <bartv@thisnet.nl>
 * This file is licensed under the Affero General Public License version 3 or
 * later.
 * See the COPYING-README file.
 */

namespace OC\DB;

/**
 * This handles the way we use to write queries, into something that can be
 * handled by the database abstraction layer.
 */
class Adapter {

	/**
	 * @var \OC\DB\Connection $conn
	 */
	protected $conn;

	public function __construct($conn) {
		$this->conn = $conn;
	}

	/**
	 * @param string $table name
	 * @return int id of last insert statement
	 */
	public function lastInsertId($table) {
		return $this->conn->realLastInsertId($table);
	}

	/**
	 * @param string $statement that needs to be changed so the db can handle it
	 * @return string changed statement
	 */
	public function fixupStatement($statement) {
		return $statement;
	}

	/**
	 * insert the @input values when they do not exist yet
	 * @param string $table name
	 * @param array $input key->value pair, key has to be sanitized properly
	 * @throws \OC\HintException
	 * @return int count of inserted rows
	 */
	public function insertIfNotExist($table, $input, $compare = null) {
		if ($compare === null) {
			$compare = array_keys($input);
		}
		$query = 'INSERT INTO `' .$table . '` (`'
			. implode('`,`', array_keys($input)) . '`) SELECT '
			. str_repeat('?,', count($input)-1).'? ' // Is there a prettier alternative?
			. 'FROM `' . $table . '` WHERE ';

		$inserts = array_values($input);
		foreach($compare as $key) {
			$query .= '`' . $key . '`';
			if (is_null($input[$key])) {
				$query .= ' IS NULL AND ';
			} else {
				$inserts[] = $input[$key];
				$query .= ' = ? AND ';
			}
		}
		$query = substr($query, 0, strlen($query) - 5);
		$query .= ' HAVING COUNT(*) = 0';

		try {
			return $this->conn->executeUpdate($query, $inserts);
		} catch(\Doctrine\DBAL\DBALException $e) {
			$entry = 'DB Error: "'.$e->getMessage() . '"<br />';
			$entry .= 'Offending command was: ' . $query.'<br />';
			\OC_Log::write('core', $entry, \OC_Log::FATAL);
			$l = \OC::$server->getL10N('lib');
			throw new \OC\HintException(
				$l->t('Database Error'),
				$l->t('Please contact your system administrator.'),
				0,
				$e
			);
		}
	}
}