Class overview¶

Doctrine provides a set of php objects to represent, create and handle SQL queries and their results. The basic class structure was slightly enriched by TYPO3 to add CMS specific features. Extension authors will typically interact with these classes and objects:

Connection: TYPO3\CMS\Core\Database\Connection: Object representing a specific connection to one connected database. Provides "shortcut" methods for simple standard queries like SELECT or UPDATE. An instance of the QueryBuilder can be retrieved to build more complex queries.
ConnectionPool: TYPO3\CMS\Core\Database\ConnectionPool: Main entry point for extensions to retrieve a specific connection a query should be executed on. Typically used to return a Connection or a QueryBuilder object.
ExpressionBuilder: TYPO3\CMS\Core\Database\Query\Expression\ExpressionBuilder: Object to model complex expressions. Mainly used for WHERE and JOIN conditions.
QueryBuilder: TYPO3\CMS\Core\Database\Query\QueryBuilder: Object to create all sort of complex queries executed on a specific connection. Provides the main CRUD methods for select(), delete() and friends.
QueryHelper: TYPO3\CMS\Core\Database\Query\QueryHelper: Set of static helper methods that can simplify the transition from old TYPO3_DB based code to the doctrine base API.
Restriction ...: TYPO3\CMS\Core\Database\Query\Restriction\...: Set of classes that add expressions like "deleted=0" to a query based on TCA settings of a table. This automatically adds TYPO3 specific restrictions like starttime and endtime, as well as deleted and hidden flags. Further restrictions for language overlays and workspaces are available. This documentation refers to these classes as the RestrictionBuilder.
Statement: Doctrine\DBAL\Driver\Statement: Result object retrieved if a SELECT or COUNT query has been executed. Single rows are returned as array by calling ->fetch() until the method returns false.