diff --git a/apps/dav/tests/unit/CalDAV/ResourceBooking/AbstractPrincipalBackendTest.php b/apps/dav/tests/unit/CalDAV/ResourceBooking/AbstractPrincipalBackendTest.php
index 19da1782cc..eb9faa574a 100644
--- a/apps/dav/tests/unit/CalDAV/ResourceBooking/AbstractPrincipalBackendTest.php
+++ b/apps/dav/tests/unit/CalDAV/ResourceBooking/AbstractPrincipalBackendTest.php
@@ -22,7 +22,6 @@
 namespace OCA\DAV\Tests\unit\CalDAV\ResourceBooking;
 
 use OCP\DB\QueryBuilder\IQueryBuilder;
-use OCP\IDBConnection;
 use OCP\IGroupManager;
 use OCP\ILogger;
 use OCP\IUser;
@@ -35,9 +34,6 @@ abstract class AbstractPrincipalBackendTest extends TestCase {
 	/** @var \OCA\DAV\CalDAV\ResourceBooking\ResourcePrincipalBackend|\OCA\DAV\CalDAV\ResourceBooking\RoomPrincipalBackend */
 	protected $principalBackend;
 
-	/** @var IDBConnection|\PHPUnit_Framework_MockObject_MockObject */
-	protected $dbConnection;
-
 	/** @var IUserSession|\PHPUnit_Framework_MockObject_MockObject */
 	protected $userSession;
 
@@ -48,7 +44,13 @@ abstract class AbstractPrincipalBackendTest extends TestCase {
 	protected $logger;
 
 	/** @var string */
-	protected $expectedDbTable;
+	protected $mainDbTable;
+
+	/** @var string */
+	protected $metadataDbTable;
+
+	/** @var string */
+	protected $foreignKey;
 
 	/** @var string */
 	protected $principalPrefix;
@@ -59,222 +61,92 @@ abstract class AbstractPrincipalBackendTest extends TestCase {
 	public function setUp() {
 		parent::setUp();
 
-		$this->dbConnection = $this->createMock(IDBConnection::class);
 		$this->userSession = $this->createMock(IUserSession::class);
 		$this->groupManager = $this->createMock(IGroupManager::class);
 		$this->logger = $this->createMock(ILogger::class);
 	}
 
+	protected function tearDown() {
+		$query = self::$realDatabase->getQueryBuilder();
+
+		$query->delete('calendar_resources')->execute();
+		$query->delete('calendar_resources_md')->execute();
+		$query->delete('calendar_rooms')->execute();
+		$query->delete('calendar_rooms_md')->execute();
+	}
+
 	public function testGetPrincipalsByPrefix() {
-		$queryBuilder = $this->createMock(IQueryBuilder::class);
-		$stmt = $this->createMock(\Doctrine\DBAL\Driver\Statement::class);
-		$this->dbConnection->expects($this->once())
-			->method('getQueryBuilder')
-			->with()
-			->will($this->returnValue($queryBuilder));
-
-		$queryBuilder->expects($this->at(0))
-			->method('select')
-			->with(['id', 'backend_id', 'resource_id', 'email', 'displayname'])
-			->will($this->returnValue($queryBuilder));
-		$queryBuilder->expects($this->at(1))
-			->method('from')
-			->with($this->expectedDbTable)
-			->will($this->returnValue($queryBuilder));
-		$queryBuilder->expects($this->at(2))
-			->method('execute')
-			->with()
-			->will($this->returnValue($stmt));
-
-		$stmt->expects($this->at(0))
-			->method('fetch')
-			->with(\PDO::FETCH_ASSOC)
-			->will($this->returnValue([
-				'id' => 0,
-				'backend_id' => 'db',
-				'resource_id' => '123',
-				'email' => 'foo@bar.com',
-				'displayname' => 'Resource 123'
-			]));
-		$stmt->expects($this->at(1))
-			->method('fetch')
-			->with(\PDO::FETCH_ASSOC)
-			->will($this->returnValue([
-				'id' => 1,
-				'backend_id' => 'ldap',
-				'resource_id' => '123',
-				'email' => 'ldap@bar.com',
-				'displayname' => 'Resource 123 ldap'
-			]));
-		$stmt->expects($this->at(2))
-			->method('fetch')
-			->with(\PDO::FETCH_ASSOC)
-			->will($this->returnValue([
-				'id' => 2,
-				'backend_id' => 'db',
-				'resource_id' => '456',
-				'email' => 'bli@bar.com',
-				'displayname' => 'Resource 456'
-			]));
-		$stmt->expects($this->at(3))
-			->method('fetch')
-			->with(\PDO::FETCH_ASSOC)
-			->will($this->returnValue(null));
-		$stmt->expects($this->at(4))
-			->method('closeCursor')
-			->with();
-
 		$actual = $this->principalBackend->getPrincipalsByPrefix($this->principalPrefix);
+
 		$this->assertEquals([
 			[
-				'uri' => $this->principalPrefix . '/db-123',
-				'{DAV:}displayname' => 'Resource 123',
-				'{http://sabredav.org/ns}email-address' => 'foo@bar.com',
+				'uri' => $this->principalPrefix . '/backend1-res1',
+				'{DAV:}displayname' => 'Beamer1',
+				'{http://sabredav.org/ns}email-address' => 'res1@foo.bar',
 				'{urn:ietf:params:xml:ns:caldav}calendar-user-type' => $this->expectedCUType,
 			],
 			[
-				'uri' => $this->principalPrefix . '/ldap-123',
-				'{DAV:}displayname' => 'Resource 123 ldap',
-				'{http://sabredav.org/ns}email-address' => 'ldap@bar.com',
+				'uri' => $this->principalPrefix . '/backend1-res2',
+				'{DAV:}displayname' => 'TV1',
+				'{http://sabredav.org/ns}email-address' => 'res2@foo.bar',
 				'{urn:ietf:params:xml:ns:caldav}calendar-user-type' => $this->expectedCUType,
 			],
 			[
-				'uri' => $this->principalPrefix . '/db-456',
-				'{DAV:}displayname' => 'Resource 456',
-				'{http://sabredav.org/ns}email-address' => 'bli@bar.com',
+				'uri' => $this->principalPrefix . '/backend2-res3',
+				'{DAV:}displayname' => 'Beamer2',
+				'{http://sabredav.org/ns}email-address' => 'res3@foo.bar',
+				'{urn:ietf:params:xml:ns:caldav}calendar-user-type' => $this->expectedCUType,
+				'{http://nextcloud.com/ns}foo' => 'value1',
+				'{http://nextcloud.com/ns}meta2' => 'value2',
+			],
+			[
+				'uri' => $this->principalPrefix . '/backend2-res4',
+				'{DAV:}displayname' => 'TV2',
+				'{http://sabredav.org/ns}email-address' => 'res4@foo.bar',
+				'{urn:ietf:params:xml:ns:caldav}calendar-user-type' => $this->expectedCUType,
+				'{http://nextcloud.com/ns}meta1' => 'value1',
+				'{http://nextcloud.com/ns}meta3' => 'value3-old',
+			],
+			[
+				'uri' => $this->principalPrefix . '/backend3-res5',
+				'{DAV:}displayname' => 'Beamer3',
+				'{http://sabredav.org/ns}email-address' => 'res5@foo.bar',
 				'{urn:ietf:params:xml:ns:caldav}calendar-user-type' => $this->expectedCUType,
 			],
+			[
+				'uri' => $this->principalPrefix . '/backend3-res6',
+				'{DAV:}displayname' => 'Pointer',
+				'{http://sabredav.org/ns}email-address' => 'res6@foo.bar',
+				'{urn:ietf:params:xml:ns:caldav}calendar-user-type' => $this->expectedCUType,
+				'{http://nextcloud.com/ns}meta99' => 'value99'
+			]
 		], $actual);
 
 	}
 
 	public function testGetNoPrincipalsByPrefixForWrongPrincipalPrefix() {
-		$this->dbConnection->expects($this->never())
-			->method('getQueryBuilder');
-
 		$actual = $this->principalBackend->getPrincipalsByPrefix('principals/users');
 		$this->assertEquals([], $actual);
 	}
 
 	public function testGetPrincipalByPath() {
-		$queryBuilder = $this->createMock(IQueryBuilder::class);
-		$stmt = $this->createMock(\Doctrine\DBAL\Driver\Statement::class);
-		$expr = $this->createMock(\OCP\DB\QueryBuilder\IExpressionBuilder::class);
-
-		$this->dbConnection->expects($this->at(0))
-			->method('getQueryBuilder')
-			->with()
-			->will($this->returnValue($queryBuilder));
-		$queryBuilder->method('expr')
-			->will($this->returnValue($expr));
-		$expr->method('eq')
-			->will($this->returnValueMap([
-				['backend_id', 'createNamedParameter-1', null, 'WHERE_CLAUSE_1'],
-				['resource_id', 'createNamedParameter-2', null, 'WHERE_CLAUSE_2'],
-			]));
-		$queryBuilder->method('createNamedParameter')
-			->will($this->returnValueMap([
-				['db', \PDO::PARAM_STR, null, 'createNamedParameter-1'],
-				['123', \PDO::PARAM_STR, null, 'createNamedParameter-2'],
-			]));
-
-		$queryBuilder->expects($this->at(0))
-			->method('select')
-			->with(['id', 'backend_id', 'resource_id', 'email', 'displayname'])
-			->will($this->returnValue($queryBuilder));
-		$queryBuilder->expects($this->at(1))
-			->method('from')
-			->with($this->expectedDbTable)
-			->will($this->returnValue($queryBuilder));
-		$queryBuilder->expects($this->at(4))
-			->method('where')
-			->with('WHERE_CLAUSE_1')
-			->will($this->returnValue($queryBuilder));
-		$queryBuilder->expects($this->at(7))
-			->method('andWhere')
-			->with('WHERE_CLAUSE_2')
-			->will($this->returnValue($queryBuilder));
-		$queryBuilder->expects($this->at(8))
-			->method('execute')
-			->with()
-			->will($this->returnValue($stmt));
-
-		$stmt->expects($this->at(0))
-			->method('fetch')
-			->with(\PDO::FETCH_ASSOC)
-			->will($this->returnValue([
-				'id' => 0,
-				'backend_id' => 'db',
-				'resource_id' => '123',
-				'email' => 'foo@bar.com',
-				'displayname' => 'Resource 123'
-			]));
-
-		$actual = $this->principalBackend->getPrincipalByPath($this->principalPrefix . '/db-123');
+		$actual = $this->principalBackend->getPrincipalByPath($this->principalPrefix . '/backend2-res3');
 		$this->assertEquals([
-			'uri' => $this->principalPrefix . '/db-123',
-			'{DAV:}displayname' => 'Resource 123',
-			'{http://sabredav.org/ns}email-address' => 'foo@bar.com',
+			'uri' => $this->principalPrefix . '/backend2-res3',
+			'{DAV:}displayname' => 'Beamer2',
+			'{http://sabredav.org/ns}email-address' => 'res3@foo.bar',
 			'{urn:ietf:params:xml:ns:caldav}calendar-user-type' => $this->expectedCUType,
+			'{http://nextcloud.com/ns}foo' => 'value1',
+			'{http://nextcloud.com/ns}meta2' => 'value2',
 		], $actual);
 	}
 
 	public function testGetPrincipalByPathNotFound() {
-		$queryBuilder = $this->createMock(IQueryBuilder::class);
-		$stmt = $this->createMock(\Doctrine\DBAL\Driver\Statement::class);
-		$expr = $this->createMock(\OCP\DB\QueryBuilder\IExpressionBuilder::class);
-
-		$this->dbConnection->expects($this->at(0))
-			->method('getQueryBuilder')
-			->with()
-			->will($this->returnValue($queryBuilder));
-		$queryBuilder->method('expr')
-			->will($this->returnValue($expr));
-		$expr->method('eq')
-			->will($this->returnValueMap([
-				['backend_id', 'createNamedParameter-1', null, 'WHERE_CLAUSE_1'],
-				['resource_id', 'createNamedParameter-2', null, 'WHERE_CLAUSE_2'],
-			]));
-		$queryBuilder->method('createNamedParameter')
-			->will($this->returnValueMap([
-				['db', \PDO::PARAM_STR, null, 'createNamedParameter-1'],
-				['123', \PDO::PARAM_STR, null, 'createNamedParameter-2'],
-			]));
-
-		$queryBuilder->expects($this->at(0))
-			->method('select')
-			->with(['id', 'backend_id', 'resource_id', 'email', 'displayname'])
-			->will($this->returnValue($queryBuilder));
-		$queryBuilder->expects($this->at(1))
-			->method('from')
-			->with($this->expectedDbTable)
-			->will($this->returnValue($queryBuilder));
-		$queryBuilder->expects($this->at(4))
-			->method('where')
-			->with('WHERE_CLAUSE_1')
-			->will($this->returnValue($queryBuilder));
-		$queryBuilder->expects($this->at(7))
-			->method('andWhere')
-			->with('WHERE_CLAUSE_2')
-			->will($this->returnValue($queryBuilder));
-		$queryBuilder->expects($this->at(8))
-			->method('execute')
-			->with()
-			->will($this->returnValue($stmt));
-
-		$stmt->expects($this->at(0))
-			->method('fetch')
-			->with(\PDO::FETCH_ASSOC)
-			->will($this->returnValue(false));
-
 		$actual = $this->principalBackend->getPrincipalByPath($this->principalPrefix . '/db-123');
 		$this->assertEquals(null, $actual);
 	}
 
 	public function testGetPrincipalByPathWrongPrefix() {
-		$this->dbConnection->expects($this->never())
-			->method('getQueryBuilder');
-
 		$actual = $this->principalBackend->getPrincipalByPath('principals/users/foo-bar');
 		$this->assertEquals(null, $actual);
 	}
@@ -318,182 +190,9 @@ abstract class AbstractPrincipalBackendTest extends TestCase {
 			->with($user)
 			->will($this->returnValue(['group1', 'group2']));
 
-		$queryBuilder1 = $this->createMock(IQueryBuilder::class);
-		$queryBuilder2 = $this->createMock(IQueryBuilder::class);
-		$stmt1 = $this->createMock(\Doctrine\DBAL\Driver\Statement::class);
-		$stmt2 = $this->createMock(\Doctrine\DBAL\Driver\Statement::class);
-		$expr1 = $this->createMock(\OCP\DB\QueryBuilder\IExpressionBuilder::class);
-		$expr2 = $this->createMock(\OCP\DB\QueryBuilder\IExpressionBuilder::class);
-
-		$this->dbConnection->expects($this->at(0))
-			->method('getQueryBuilder')
-			->with()
-			->will($this->returnValue($queryBuilder1));
-		$this->dbConnection->expects($this->at(1))
-			->method('escapeLikeParameter')
-			->with('foo')
-			->will($this->returnValue('escapedFoo'));
-		$this->dbConnection->expects($this->at(2))
-			->method('getQueryBuilder')
-			->with()
-			->will($this->returnValue($queryBuilder2));
-		$this->dbConnection->expects($this->at(3))
-			->method('escapeLikeParameter')
-			->with('bar')
-			->will($this->returnValue('escapedBar'));
-
-		$queryBuilder1->method('expr')
-			->will($this->returnValue($expr1));
-		$queryBuilder2->method('expr')
-			->will($this->returnValue($expr2));
-
-		$expr1->method('iLike')
-			->will($this->returnValueMap([
-				['email', 'createNamedParameter-1', null, 'ILIKE_CLAUSE_1'],
-			]));
-		$expr2->method('iLike')
-			->will($this->returnValueMap([
-				['displayname', 'createNamedParameter-2', null, 'ILIKE_CLAUSE_2'],
-			]));
-
-		$queryBuilder1->method('expr')
-			->will($this->returnValue($expr1));
-		$queryBuilder2->method('expr')
-			->will($this->returnValue($expr2));
-
-		$queryBuilder1->method('createNamedParameter')
-			->will($this->returnValueMap([
-				['%escapedFoo%', \PDO::PARAM_STR, null, 'createNamedParameter-1'],
-			]));
-		$queryBuilder2->method('createNamedParameter')
-			->will($this->returnValueMap([
-				['%escapedBar%', \PDO::PARAM_STR, null, 'createNamedParameter-2'],
-			]));
-
-		$queryBuilder1->expects($this->at(0))
-			->method('select')
-			->with(['id', 'backend_id', 'resource_id', 'email', 'displayname', 'group_restrictions'])
-			->will($this->returnValue($queryBuilder1));
-		$queryBuilder1->expects($this->at(1))
-			->method('from')
-			->with($this->expectedDbTable)
-			->will($this->returnValue($queryBuilder1));
-		$queryBuilder1->expects($this->at(4))
-			->method('where')
-			->with('ILIKE_CLAUSE_1')
-			->will($this->returnValue($queryBuilder1));
-		$queryBuilder1->expects($this->at(5))
-			->method('execute')
-			->with()
-			->will($this->returnValue($stmt1));
-
-		$queryBuilder2->expects($this->at(0))
-			->method('select')
-			->with(['id', 'backend_id', 'resource_id', 'email', 'displayname', 'group_restrictions'])
-			->will($this->returnValue($queryBuilder2));
-		$queryBuilder2->expects($this->at(1))
-			->method('from')
-			->with($this->expectedDbTable)
-			->will($this->returnValue($queryBuilder2));
-		$queryBuilder2->expects($this->at(4))
-			->method('where')
-			->with('ILIKE_CLAUSE_2')
-			->will($this->returnValue($queryBuilder2));
-		$queryBuilder2->expects($this->at(5))
-			->method('execute')
-			->with()
-			->will($this->returnValue($stmt2));
-
-		$stmt1->expects($this->at(0))
-			->method('fetch')
-			->with(\PDO::FETCH_ASSOC)
-			->will($this->returnValue([
-				'id' => 0,
-				'backend_id' => 'db',
-				'resource_id' => '1',
-				'email' => '1',
-				'displayname' => 'Resource 1',
-				'group_restrictions' => null,
-			]));
-		$stmt1->expects($this->at(1))
-			->method('fetch')
-			->with(\PDO::FETCH_ASSOC)
-			->will($this->returnValue([
-				'id' => 1,
-				'backend_id' => 'db',
-				'resource_id' => '2',
-				'email' => '2',
-				'displayname' => 'Resource 2',
-				'group_restrictions' => '',
-			]));
-		$stmt1->expects($this->at(2))
-			->method('fetch')
-			->with(\PDO::FETCH_ASSOC)
-			->will($this->returnValue([
-				'id' => 2,
-				'backend_id' => 'db',
-				'resource_id' => '3',
-				'email' => '3',
-				'displayname' => 'Resource 3',
-				'group_restrictions' => '["group3"]',
-			]));
-		$stmt1->expects($this->at(3))
-			->method('fetch')
-			->with(\PDO::FETCH_ASSOC)
-			->will($this->returnValue([
-				'id' => 99,
-				'backend_id' => 'db',
-				'resource_id' => '99',
-				'email' => '99',
-				'displayname' => 'Resource 99',
-				'group_restrictions' => '["group1", "group2"]',
-			]));
-		$stmt1->expects($this->at(4))
-			->method('fetch')
-			->with(\PDO::FETCH_ASSOC)
-			->will($this->returnValue(null));
-
-		$stmt2->expects($this->at(0))
-			->method('fetch')
-			->with(\PDO::FETCH_ASSOC)
-			->will($this->returnValue([
-				'id' => 0,
-				'backend_id' => 'db',
-				'resource_id' => '4',
-				'email' => '4',
-				'displayname' => 'Resource 4',
-				'group_restrictions' => '[]'
-			]));
-		$stmt2->expects($this->at(1))
-			->method('fetch')
-			->with(\PDO::FETCH_ASSOC)
-			->will($this->returnValue([
-				'id' => 1,
-				'backend_id' => 'db',
-				'resource_id' => '5',
-				'email' => '5',
-				'displayname' => 'Resource 5',
-				'group_restrictions' => '["group1", "group5"]'
-			]));
-		$stmt2->expects($this->at(2))
-			->method('fetch')
-			->with(\PDO::FETCH_ASSOC)
-			->will($this->returnValue([
-				'id' => 99,
-				'backend_id' => 'db',
-				'resource_id' => '99',
-				'email' => '99',
-				'displayname' => 'Resource 99',
-				'group_restrictions' => '["group1", "group2"]',
-			]));
-		$stmt2->expects($this->at(3))
-			->method('fetch')
-			->with(\PDO::FETCH_ASSOC)
-			->will($this->returnValue(null));
-
 		$actual = $this->principalBackend->searchPrincipals($this->principalPrefix, [
 			'{http://sabredav.org/ns}email-address' => 'foo',
-			'{DAV:}displayname' => 'bar',
+			'{DAV:}displayname' => 'Beamer',
 		], $test);
 
 		$this->assertEquals(
@@ -507,133 +206,35 @@ abstract class AbstractPrincipalBackendTest extends TestCase {
 		// at that point, so we need this hack
 		return [
 			[[
-				'%prefix%/db-99'
+				'%prefix%/backend1-res1',
+				'%prefix%/backend2-res3',
 			], 'allof'],
 			[[
-				'%prefix%/db-1',
-				'%prefix%/db-2',
-				'%prefix%/db-99',
-				'%prefix%/db-4',
-				'%prefix%/db-5',
+				'%prefix%/backend1-res1',
+				'%prefix%/backend1-res2',
+				'%prefix%/backend2-res3',
+				'%prefix%/backend2-res4',
+				'%prefix%/backend3-res6',
 			], 'anyof'],
 		];
 	}
 
 	public function testSearchPrincipalsByCalendarUserAddressSet() {
 		$user = $this->createMock(IUser::class);
-		$this->userSession->expects($this->exactly(2))
-			->method('getUser')
+		$this->userSession->method('getUser')
 			->with()
 			->will($this->returnValue($user));
-		$this->groupManager->expects($this->exactly(2))
-			->method('getUserGroupIds')
+		$this->groupManager->method('getUserGroupIds')
 			->with($user)
 			->will($this->returnValue(['group1', 'group2']));
 
-		$queryBuilder1 = $this->createMock(IQueryBuilder::class);
-		$stmt1 = $this->createMock(\Doctrine\DBAL\Driver\Statement::class);
-		$expr1 = $this->createMock(\OCP\DB\QueryBuilder\IExpressionBuilder::class);
-
-		$this->dbConnection->expects($this->at(0))
-			->method('getQueryBuilder')
-			->with()
-			->will($this->returnValue($queryBuilder1));
-		$this->dbConnection->expects($this->at(1))
-			->method('escapeLikeParameter')
-			->with('foo')
-			->will($this->returnValue('escapedFoo'));
-
-		$queryBuilder1->method('expr')
-			->will($this->returnValue($expr1));
-
-		$expr1->method('iLike')
-			->will($this->returnValueMap([
-				['email', 'createNamedParameter-1', null, 'ILIKE_CLAUSE_1'],
-			]));
-
-		$queryBuilder1->method('expr')
-			->will($this->returnValue($expr1));
-
-		$queryBuilder1->method('createNamedParameter')
-			->will($this->returnValueMap([
-				['%escapedFoo%', \PDO::PARAM_STR, null, 'createNamedParameter-1'],
-			]));
-
-		$queryBuilder1->expects($this->at(0))
-			->method('select')
-			->with(['id', 'backend_id', 'resource_id', 'email', 'displayname', 'group_restrictions'])
-			->will($this->returnValue($queryBuilder1));
-		$queryBuilder1->expects($this->at(1))
-			->method('from')
-			->with($this->expectedDbTable)
-			->will($this->returnValue($queryBuilder1));
-		$queryBuilder1->expects($this->at(4))
-			->method('where')
-			->with('ILIKE_CLAUSE_1')
-			->will($this->returnValue($queryBuilder1));
-		$queryBuilder1->expects($this->at(5))
-			->method('execute')
-			->with()
-			->will($this->returnValue($stmt1));
-
-		$stmt1->expects($this->at(0))
-			->method('fetch')
-			->with(\PDO::FETCH_ASSOC)
-			->will($this->returnValue([
-				'id' => 0,
-				'backend_id' => 'db',
-				'resource_id' => '1',
-				'email' => '1',
-				'displayname' => 'Resource 1',
-				'group_restrictions' => null,
-			]));
-		$stmt1->expects($this->at(1))
-			->method('fetch')
-			->with(\PDO::FETCH_ASSOC)
-			->will($this->returnValue([
-				'id' => 1,
-				'backend_id' => 'db',
-				'resource_id' => '2',
-				'email' => '2',
-				'displayname' => 'Resource 2',
-				'group_restrictions' => '',
-			]));
-		$stmt1->expects($this->at(2))
-			->method('fetch')
-			->with(\PDO::FETCH_ASSOC)
-			->will($this->returnValue([
-				'id' => 2,
-				'backend_id' => 'db',
-				'resource_id' => '3',
-				'email' => '3',
-				'displayname' => 'Resource 3',
-				'group_restrictions' => '["group3"]',
-			]));
-		$stmt1->expects($this->at(3))
-			->method('fetch')
-			->with(\PDO::FETCH_ASSOC)
-			->will($this->returnValue([
-				'id' => 99,
-				'backend_id' => 'db',
-				'resource_id' => '99',
-				'email' => '99',
-				'displayname' => 'Resource 99',
-				'group_restrictions' => '["group1", "group2"]',
-			]));
-		$stmt1->expects($this->at(4))
-			->method('fetch')
-			->with(\PDO::FETCH_ASSOC)
-			->will($this->returnValue(null));
-
 		$actual = $this->principalBackend->searchPrincipals($this->principalPrefix, [
-			'{urn:ietf:params:xml:ns:caldav}calendar-user-address-set' => 'foo',
+			'{urn:ietf:params:xml:ns:caldav}calendar-user-address-set' => 'res2@foo.bar',
 		]);
 
 		$this->assertEquals(
 			str_replace('%prefix%', $this->principalPrefix, [
-				'%prefix%/db-1',
-				'%prefix%/db-2',
-				'%prefix%/db-99',
+				'%prefix%/backend1-res2',
 			]),
 			$actual);
 	}
@@ -643,8 +244,6 @@ abstract class AbstractPrincipalBackendTest extends TestCase {
 			->method('getUser');
 		$this->groupManager->expects($this->never())
 			->method('getUserGroupIds');
-		$this->dbConnection->expects($this->never())
-			->method('getQueryBuilder');
 
 		$this->principalBackend->searchPrincipals($this->principalPrefix, []);
 	}
@@ -654,8 +253,6 @@ abstract class AbstractPrincipalBackendTest extends TestCase {
 			->method('getUser');
 		$this->groupManager->expects($this->never())
 			->method('getUserGroupIds');
-		$this->dbConnection->expects($this->never())
-			->method('getQueryBuilder');
 
 		$this->principalBackend->searchPrincipals('principals/users', [
 			'{http://sabredav.org/ns}email-address' => 'foo'
@@ -673,56 +270,8 @@ abstract class AbstractPrincipalBackendTest extends TestCase {
 			->with($user)
 			->will($this->returnValue(['group1', 'group2']));
 
-		$queryBuilder = $this->createMock(IQueryBuilder::class);
-		$stmt = $this->createMock(\Doctrine\DBAL\Driver\Statement::class);
-		$expr = $this->createMock(\OCP\DB\QueryBuilder\IExpressionBuilder::class);
-
-		$this->dbConnection->expects($this->at(0))
-			->method('getQueryBuilder')
-			->with()
-			->will($this->returnValue($queryBuilder));
-		$queryBuilder->method('expr')
-			->will($this->returnValue($expr));
-		$expr->method('eq')
-			->will($this->returnValueMap([
-				['email', 'createNamedParameter-1', null, 'WHERE_CLAUSE_1'],
-			]));
-		$queryBuilder->method('createNamedParameter')
-			->will($this->returnValueMap([
-				['foo@bar.com', \PDO::PARAM_STR, null, 'createNamedParameter-1'],
-			]));
-
-		$queryBuilder->expects($this->at(0))
-			->method('select')
-			->with(['id', 'backend_id', 'resource_id', 'email', 'displayname', 'group_restrictions'])
-			->will($this->returnValue($queryBuilder));
-		$queryBuilder->expects($this->at(1))
-			->method('from')
-			->with($this->expectedDbTable)
-			->will($this->returnValue($queryBuilder));
-		$queryBuilder->expects($this->at(4))
-			->method('where')
-			->with('WHERE_CLAUSE_1')
-			->will($this->returnValue($queryBuilder));
-		$queryBuilder->expects($this->at(5))
-			->method('execute')
-			->with()
-			->will($this->returnValue($stmt));
-
-		$stmt->expects($this->at(0))
-			->method('fetch')
-			->with(\PDO::FETCH_ASSOC)
-			->will($this->returnValue([
-				'id' => 0,
-				'backend_id' => 'db',
-				'resource_id' => '123',
-				'email' => 'foo@bar.com',
-				'displayname' => 'Resource 123',
-				'group_restrictions' => '["group1"]',
-			]));
-
-		$actual = $this->principalBackend->findByUri('mailto:foo@bar.com', $this->principalPrefix);
-		$this->assertEquals($this->principalPrefix . '/db-123', $actual);
+		$actual = $this->principalBackend->findByUri('mailto:res1@foo.bar', $this->principalPrefix);
+		$this->assertEquals($this->principalPrefix . '/backend1-res1', $actual);
 	}
 
 	public function testFindByUriByEmailForbiddenResource() {
@@ -736,55 +285,7 @@ abstract class AbstractPrincipalBackendTest extends TestCase {
 			->with($user)
 			->will($this->returnValue(['group1', 'group2']));
 
-		$queryBuilder = $this->createMock(IQueryBuilder::class);
-		$stmt = $this->createMock(\Doctrine\DBAL\Driver\Statement::class);
-		$expr = $this->createMock(\OCP\DB\QueryBuilder\IExpressionBuilder::class);
-
-		$this->dbConnection->expects($this->at(0))
-			->method('getQueryBuilder')
-			->with()
-			->will($this->returnValue($queryBuilder));
-		$queryBuilder->method('expr')
-			->will($this->returnValue($expr));
-		$expr->method('eq')
-			->will($this->returnValueMap([
-				['email', 'createNamedParameter-1', null, 'WHERE_CLAUSE_1'],
-			]));
-		$queryBuilder->method('createNamedParameter')
-			->will($this->returnValueMap([
-				['foo@bar.com', \PDO::PARAM_STR, null, 'createNamedParameter-1'],
-			]));
-
-		$queryBuilder->expects($this->at(0))
-			->method('select')
-			->with(['id', 'backend_id', 'resource_id', 'email', 'displayname', 'group_restrictions'])
-			->will($this->returnValue($queryBuilder));
-		$queryBuilder->expects($this->at(1))
-			->method('from')
-			->with($this->expectedDbTable)
-			->will($this->returnValue($queryBuilder));
-		$queryBuilder->expects($this->at(4))
-			->method('where')
-			->with('WHERE_CLAUSE_1')
-			->will($this->returnValue($queryBuilder));
-		$queryBuilder->expects($this->at(5))
-			->method('execute')
-			->with()
-			->will($this->returnValue($stmt));
-
-		$stmt->expects($this->at(0))
-			->method('fetch')
-			->with(\PDO::FETCH_ASSOC)
-			->will($this->returnValue([
-				'id' => 0,
-				'backend_id' => 'db',
-				'resource_id' => '123',
-				'email' => 'foo@bar.com',
-				'displayname' => 'Resource 123',
-				'group_restrictions' => '["group3"]',
-			]));
-
-		$actual = $this->principalBackend->findByUri('mailto:foo@bar.com', $this->principalPrefix);
+		$actual = $this->principalBackend->findByUri('mailto:res5@foo.bar', $this->principalPrefix);
 		$this->assertEquals(null, $actual);
 	}
 
@@ -799,48 +300,7 @@ abstract class AbstractPrincipalBackendTest extends TestCase {
 			->with($user)
 			->will($this->returnValue(['group1', 'group2']));
 
-		$queryBuilder = $this->createMock(IQueryBuilder::class);
-		$stmt = $this->createMock(\Doctrine\DBAL\Driver\Statement::class);
-		$expr = $this->createMock(\OCP\DB\QueryBuilder\IExpressionBuilder::class);
-
-		$this->dbConnection->expects($this->at(0))
-			->method('getQueryBuilder')
-			->with()
-			->will($this->returnValue($queryBuilder));
-		$queryBuilder->method('expr')
-			->will($this->returnValue($expr));
-		$expr->method('eq')
-			->will($this->returnValueMap([
-				['email', 'createNamedParameter-1', null, 'WHERE_CLAUSE_1'],
-			]));
-		$queryBuilder->method('createNamedParameter')
-			->will($this->returnValueMap([
-				['foo@bar.com', \PDO::PARAM_STR, null, 'createNamedParameter-1'],
-			]));
-
-		$queryBuilder->expects($this->at(0))
-			->method('select')
-			->with(['id', 'backend_id', 'resource_id', 'email', 'displayname', 'group_restrictions'])
-			->will($this->returnValue($queryBuilder));
-		$queryBuilder->expects($this->at(1))
-			->method('from')
-			->with($this->expectedDbTable)
-			->will($this->returnValue($queryBuilder));
-		$queryBuilder->expects($this->at(4))
-			->method('where')
-			->with('WHERE_CLAUSE_1')
-			->will($this->returnValue($queryBuilder));
-		$queryBuilder->expects($this->at(5))
-			->method('execute')
-			->with()
-			->will($this->returnValue($stmt));
-
-		$stmt->expects($this->at(0))
-			->method('fetch')
-			->with(\PDO::FETCH_ASSOC)
-			->will($this->returnValue(null));
-
-		$actual = $this->principalBackend->findByUri('mailto:foo@bar.com', $this->principalPrefix);
+		$actual = $this->principalBackend->findByUri('mailto:res99@foo.bar', $this->principalPrefix);
 		$this->assertEquals(null, $actual);
 	}
 
@@ -855,56 +315,8 @@ abstract class AbstractPrincipalBackendTest extends TestCase {
 			->with($user)
 			->will($this->returnValue(['group1', 'group2']));
 
-		$queryBuilder = $this->createMock(IQueryBuilder::class);
-		$stmt = $this->createMock(\Doctrine\DBAL\Driver\Statement::class);
-		$expr = $this->createMock(\OCP\DB\QueryBuilder\IExpressionBuilder::class);
-
-		$this->dbConnection->expects($this->at(0))
-			->method('getQueryBuilder')
-			->with()
-			->will($this->returnValue($queryBuilder));
-		$queryBuilder->method('expr')
-			->will($this->returnValue($expr));
-		$expr->method('eq')
-			->will($this->returnValueMap([
-				['email', 'createNamedParameter-1', null, 'WHERE_CLAUSE_1'],
-			]));
-		$queryBuilder->method('createNamedParameter')
-			->will($this->returnValueMap([
-				['foo@bar.com', \PDO::PARAM_STR, null, 'createNamedParameter-1'],
-			]));
-
-		$queryBuilder->expects($this->at(0))
-			->method('select')
-			->with(['id', 'backend_id', 'resource_id', 'email', 'displayname', 'group_restrictions'])
-			->will($this->returnValue($queryBuilder));
-		$queryBuilder->expects($this->at(1))
-			->method('from')
-			->with($this->expectedDbTable)
-			->will($this->returnValue($queryBuilder));
-		$queryBuilder->expects($this->at(4))
-			->method('where')
-			->with('WHERE_CLAUSE_1')
-			->will($this->returnValue($queryBuilder));
-		$queryBuilder->expects($this->at(5))
-			->method('execute')
-			->with()
-			->will($this->returnValue($stmt));
-
-		$stmt->expects($this->at(0))
-			->method('fetch')
-			->with(\PDO::FETCH_ASSOC)
-			->will($this->returnValue([
-				'id' => 0,
-				'backend_id' => 'db',
-				'resource_id' => '123',
-				'email' => 'foo@bar.com',
-				'displayname' => 'Resource 123',
-				'group_restrictions' => '["group1"]',
-			]));
-
-		$actual = $this->principalBackend->findByUri('mailto:foo@bar.com', $this->principalPrefix);
-		$this->assertEquals($this->principalPrefix . '/db-123', $actual);
+		$actual = $this->principalBackend->findByUri('mailto:res6@foo.bar', $this->principalPrefix);
+		$this->assertEquals($this->principalPrefix . '/backend3-res6', $actual);
 	}
 
 	public function testFindByUriByPrincipalForbiddenResource() {
@@ -918,61 +330,7 @@ abstract class AbstractPrincipalBackendTest extends TestCase {
 			->with($user)
 			->will($this->returnValue(['group1', 'group2']));
 
-		$queryBuilder = $this->createMock(IQueryBuilder::class);
-		$stmt = $this->createMock(\Doctrine\DBAL\Driver\Statement::class);
-		$expr = $this->createMock(\OCP\DB\QueryBuilder\IExpressionBuilder::class);
-
-		$this->dbConnection->expects($this->at(0))
-			->method('getQueryBuilder')
-			->with()
-			->will($this->returnValue($queryBuilder));
-		$queryBuilder->method('expr')
-			->will($this->returnValue($expr));
-		$expr->method('eq')
-			->will($this->returnValueMap([
-				['backend_id', 'createNamedParameter-1', null, 'WHERE_CLAUSE_1'],
-				['resource_id', 'createNamedParameter-2', null, 'WHERE_CLAUSE_2'],
-			]));
-		$queryBuilder->method('createNamedParameter')
-			->will($this->returnValueMap([
-				['db', \PDO::PARAM_STR, null, 'createNamedParameter-1'],
-				['123', \PDO::PARAM_STR, null, 'createNamedParameter-2'],
-			]));
-
-		$queryBuilder->expects($this->at(0))
-			->method('select')
-			->with(['id', 'backend_id', 'resource_id', 'email', 'displayname', 'group_restrictions'])
-			->will($this->returnValue($queryBuilder));
-		$queryBuilder->expects($this->at(1))
-			->method('from')
-			->with($this->expectedDbTable)
-			->will($this->returnValue($queryBuilder));
-		$queryBuilder->expects($this->at(4))
-			->method('where')
-			->with('WHERE_CLAUSE_1')
-			->will($this->returnValue($queryBuilder));
-		$queryBuilder->expects($this->at(7))
-			->method('andWhere')
-			->with('WHERE_CLAUSE_2')
-			->will($this->returnValue($queryBuilder));
-		$queryBuilder->expects($this->at(8))
-			->method('execute')
-			->with()
-			->will($this->returnValue($stmt));
-
-		$stmt->expects($this->at(0))
-			->method('fetch')
-			->with(\PDO::FETCH_ASSOC)
-			->will($this->returnValue([
-				'id' => 0,
-				'backend_id' => 'db',
-				'resource_id' => '123',
-				'email' => 'foo@bar.com',
-				'displayname' => 'Resource 123',
-				'group_restrictions' => '["group3"]',
-			]));
-
-		$actual = $this->principalBackend->findByUri('principal:' . $this->principalPrefix . '/db-123', $this->principalPrefix);
+		$actual = $this->principalBackend->findByUri('principal:' . $this->principalPrefix . '/backend3-res5', $this->principalPrefix);
 		$this->assertEquals(null, $actual);
 	}
 
@@ -987,53 +345,6 @@ abstract class AbstractPrincipalBackendTest extends TestCase {
 			->with($user)
 			->will($this->returnValue(['group1', 'group2']));
 
-		$queryBuilder = $this->createMock(IQueryBuilder::class);
-		$stmt = $this->createMock(\Doctrine\DBAL\Driver\Statement::class);
-		$expr = $this->createMock(\OCP\DB\QueryBuilder\IExpressionBuilder::class);
-
-		$this->dbConnection->expects($this->at(0))
-			->method('getQueryBuilder')
-			->with()
-			->will($this->returnValue($queryBuilder));
-		$queryBuilder->method('expr')
-			->will($this->returnValue($expr));
-		$expr->method('eq')
-			->will($this->returnValueMap([
-				['backend_id', 'createNamedParameter-1', null, 'WHERE_CLAUSE_1'],
-				['resource_id', 'createNamedParameter-2', null, 'WHERE_CLAUSE_2'],
-			]));
-		$queryBuilder->method('createNamedParameter')
-			->will($this->returnValueMap([
-				['db', \PDO::PARAM_STR, null, 'createNamedParameter-1'],
-				['123', \PDO::PARAM_STR, null, 'createNamedParameter-2'],
-			]));
-
-		$queryBuilder->expects($this->at(0))
-			->method('select')
-			->with(['id', 'backend_id', 'resource_id', 'email', 'displayname', 'group_restrictions'])
-			->will($this->returnValue($queryBuilder));
-		$queryBuilder->expects($this->at(1))
-			->method('from')
-			->with($this->expectedDbTable)
-			->will($this->returnValue($queryBuilder));
-		$queryBuilder->expects($this->at(4))
-			->method('where')
-			->with('WHERE_CLAUSE_1')
-			->will($this->returnValue($queryBuilder));
-		$queryBuilder->expects($this->at(7))
-			->method('andWhere')
-			->with('WHERE_CLAUSE_2')
-			->will($this->returnValue($queryBuilder));
-		$queryBuilder->expects($this->at(8))
-			->method('execute')
-			->with()
-			->will($this->returnValue($stmt));
-
-		$stmt->expects($this->at(0))
-			->method('fetch')
-			->with(\PDO::FETCH_ASSOC)
-			->will($this->returnValue(null));
-
 		$actual = $this->principalBackend->findByUri('principal:' . $this->principalPrefix . '/db-123', $this->principalPrefix);
 		$this->assertEquals(null, $actual);
 	}
@@ -1053,4 +364,106 @@ abstract class AbstractPrincipalBackendTest extends TestCase {
 		$this->assertEquals(null, $actual);
 	}
 
+	protected function createTestDatasetInDb() {
+		$query = self::$realDatabase->getQueryBuilder();
+		$query->insert($this->mainDbTable)
+			->values([
+				'backend_id' => $query->createNamedParameter('backend1'),
+				'resource_id' => $query->createNamedParameter('res1'),
+				'email' => $query->createNamedParameter('res1@foo.bar'),
+				'displayname' => $query->createNamedParameter('Beamer1'),
+				'group_restrictions' => $query->createNamedParameter('[]'),
+			])
+			->execute();
+
+		$query->insert($this->mainDbTable)
+			->values([
+				'backend_id' => $query->createNamedParameter('backend1'),
+				'resource_id' => $query->createNamedParameter('res2'),
+				'email' => $query->createNamedParameter('res2@foo.bar'),
+				'displayname' => $query->createNamedParameter('TV1'),
+				'group_restrictions' => $query->createNamedParameter('[]'),
+			])
+			->execute();
+
+		$query->insert($this->mainDbTable)
+			->values([
+				'backend_id' => $query->createNamedParameter('backend2'),
+				'resource_id' => $query->createNamedParameter('res3'),
+				'email' => $query->createNamedParameter('res3@foo.bar'),
+				'displayname' => $query->createNamedParameter('Beamer2'),
+				'group_restrictions' => $query->createNamedParameter('[]'),
+			])
+			->execute();
+		$id3 = $query->getLastInsertId();
+
+		$query->insert($this->mainDbTable)
+			->values([
+				'backend_id' => $query->createNamedParameter('backend2'),
+				'resource_id' => $query->createNamedParameter('res4'),
+				'email' => $query->createNamedParameter('res4@foo.bar'),
+				'displayname' => $query->createNamedParameter('TV2'),
+				'group_restrictions' => $query->createNamedParameter('[]'),
+			])
+			->execute();
+		$id4 = $query->getLastInsertId();
+
+		$query->insert($this->mainDbTable)
+			->values([
+				'backend_id' => $query->createNamedParameter('backend3'),
+				'resource_id' => $query->createNamedParameter('res5'),
+				'email' => $query->createNamedParameter('res5@foo.bar'),
+				'displayname' => $query->createNamedParameter('Beamer3'),
+				'group_restrictions' => $query->createNamedParameter('["foo", "bar"]'),
+			])
+			->execute();
+
+		$query->insert($this->mainDbTable)
+			->values([
+				'backend_id' => $query->createNamedParameter('backend3'),
+				'resource_id' => $query->createNamedParameter('res6'),
+				'email' => $query->createNamedParameter('res6@foo.bar'),
+				'displayname' => $query->createNamedParameter('Pointer'),
+				'group_restrictions' => $query->createNamedParameter('["group1", "bar"]'),
+			])
+			->execute();
+		$id6 = $query->getLastInsertId();
+
+		$query->insert($this->metadataDbTable)
+			->values([
+				$this->foreignKey => $query->createNamedParameter($id3),
+				'key' => $query->createNamedParameter('{http://nextcloud.com/ns}foo'),
+				'value' => $query->createNamedParameter('value1')
+			])
+			->execute();
+		$query->insert($this->metadataDbTable)
+			->values([
+				$this->foreignKey => $query->createNamedParameter($id3),
+				'key' => $query->createNamedParameter('{http://nextcloud.com/ns}meta2'),
+				'value' => $query->createNamedParameter('value2')
+			])
+			->execute();
+		$query->insert($this->metadataDbTable)
+			->values([
+				$this->foreignKey => $query->createNamedParameter($id4),
+				'key' => $query->createNamedParameter('{http://nextcloud.com/ns}meta1'),
+				'value' => $query->createNamedParameter('value1')
+			])
+			->execute();
+		$query->insert($this->metadataDbTable)
+			->values([
+				$this->foreignKey => $query->createNamedParameter($id4),
+				'key' => $query->createNamedParameter('{http://nextcloud.com/ns}meta3'),
+				'value' => $query->createNamedParameter('value3-old')
+			])
+			->execute();
+		$query->insert($this->metadataDbTable)
+			->values([
+				$this->foreignKey => $query->createNamedParameter($id6),
+				'key' => $query->createNamedParameter('{http://nextcloud.com/ns}meta99'),
+				'value' => $query->createNamedParameter('value99')
+			])
+			->execute();
+	}
+
 }
diff --git a/apps/dav/tests/unit/CalDAV/ResourceBooking/ResourcePrincipalBackendTest.php b/apps/dav/tests/unit/CalDAV/ResourceBooking/ResourcePrincipalBackendTest.php
index d3c774417c..3787e4df95 100644
--- a/apps/dav/tests/unit/CalDAV/ResourceBooking/ResourcePrincipalBackendTest.php
+++ b/apps/dav/tests/unit/CalDAV/ResourceBooking/ResourcePrincipalBackendTest.php
@@ -27,10 +27,16 @@ Class ResourcePrincipalBackendTest extends AbstractPrincipalBackendTest {
 	public function setUp() {
 		parent::setUp();
 
-		$this->principalBackend = new ResourcePrincipalBackend($this->dbConnection,
+		$this->principalBackend = new ResourcePrincipalBackend(self::$realDatabase,
 			$this->userSession, $this->groupManager, $this->logger);
-		$this->expectedDbTable = 'calendar_resources';
+
+		$this->mainDbTable = 'calendar_resources';
+		$this->metadataDbTable = 'calendar_resources_md';
+		$this->foreignKey = 'resource_id';
+
 		$this->principalPrefix = 'principals/calendar-resources';
 		$this->expectedCUType = 'RESOURCE';
+
+		$this->createTestDatasetInDb();
 	}
 }
diff --git a/apps/dav/tests/unit/CalDAV/ResourceBooking/RoomPrincipalBackendTest.php b/apps/dav/tests/unit/CalDAV/ResourceBooking/RoomPrincipalBackendTest.php
index a10aaa26b3..9b259c30ad 100644
--- a/apps/dav/tests/unit/CalDAV/ResourceBooking/RoomPrincipalBackendTest.php
+++ b/apps/dav/tests/unit/CalDAV/ResourceBooking/RoomPrincipalBackendTest.php
@@ -27,10 +27,16 @@ Class RoomPrincipalBackendTest extends AbstractPrincipalBackendTest {
 	public function setUp() {
 		parent::setUp();
 
-		$this->principalBackend = new RoomPrincipalBackend($this->dbConnection,
+		$this->principalBackend = new RoomPrincipalBackend(self::$realDatabase,
 			$this->userSession, $this->groupManager, $this->logger);
-		$this->expectedDbTable = 'calendar_rooms';
+
+		$this->mainDbTable = 'calendar_rooms';
+		$this->metadataDbTable = 'calendar_rooms_md';
+		$this->foreignKey = 'room_id';
+
 		$this->principalPrefix = 'principals/calendar-rooms';
 		$this->expectedCUType = 'ROOM';
+
+		$this->createTestDatasetInDb();
 	}
 }