Connection

Introduction

The \TYPO3\CMS\Core\Database\Connection class extends the basic Doctrine DBAL \Doctrine\DBAL\Connection class and is mainly used internally in TYPO3 to establish, maintain and terminate connections to single database endpoints. These internal methods are not the scope of this documentation, since an extension developer usually does not have to deal with them.

However, for an extension developer, the class provides a list of short-hand methods that allow you to deal with query cases without the complexity of the query builder. Using these methods usually ends up in rather short and easy-to-read code. The methods have in common that they only support "equal" comparisons in WHERE conditions, that all fields and values are automatically fully quoted, and that the created queries are executed right away.

Instantiation

<?php

declare(strict_types=1);

namespace MyVendor\MyExtension\Domain\Repository;

use TYPO3\CMS\Core\Database\ConnectionPool;

final class MyTableRepository
{
    private const TABLE_NAME = 'tx_myextension_domain_model_mytable';

    private ConnectionPool $connectionPool;

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

    public function findSomething()
    {
        $connection = $this->connectionPool
            ->getConnectionForTable(self::TABLE_NAME);
    }
}

Parameter types

The parameter types are used in various places to bind values to types, for example, when using named parameters in the query builder:

// use TYPO3\CMS\Core\Database\Connection;

$queryBuilder->createNamedParameter(42, Connection::PARAM_INT);

The following parameter types are available:

\TYPO3\CMS\Core\Database\Connection::PARAM_NULL

Represents an SQL NULL data type.

\TYPO3\CMS\Core\Database\Connection::PARAM_INT

Represents an SQL INTEGER data type.

\TYPO3\CMS\Core\Database\Connection::PARAM_STR

Represents an SQL CHAR or VARCHAR data type.

\TYPO3\CMS\Core\Database\Connection::PARAM_LOB

Represents an SQL large object data type.

\TYPO3\CMS\Core\Database\Connection::PARAM_BOOL

Represents a boolean data type.

\TYPO3\CMS\Core\Database\Connection::PARAM_INT_ARRAY

Represents an array of integer values.

\TYPO3\CMS\Core\Database\Connection::PARAM_STR_ARRAY

Represents an array of string values.

The default parameter type is Connection::PARAM_STR, if this argument is omitted.

Internally, these parameter types are mapped to the types Doctrine DBAL expects.

insert()

The insert() method creates and executes an INSERT INTO statement. A (slightly simplified) example from the Registry API:

// INSERT
//     INTO `sys_registry` (`entry_namespace`, `entry_key`, `entry_value`)
//     VALUES ('aoeu', 'aoeu', 's:3:\"bar\";')
$this->connectionPool
    ->getConnectionForTable('sys_registry')
    ->insert(
        'sys_registry',
        [
            'entry_namespace' => $namespace,
            'entry_key' => $key,
            'entry_value' => serialize($value)
        ]
    );

Read how to instantiate a connection with the connection pool. See available parameter types.

Arguments of the insert() method:

1. The name of the table the row should be inserted. Required.
2. An associative array containing field/value pairs. The key is a field name, the value is the value to be inserted. All keys are quoted to field names and all values are quoted to string values. Required.

3. Specify how single values are quoted. This is useful if a date, number or similar should be inserted. Optional.

   The example below quotes the first value to an integer and the second one to a string:

   EXT:my_extension/Classes/Domain/Repository/MyTableRepository.php

   // use TYPO3\CMS\Core\Database\Connection;
   // INSERT INTO `sys_log` (`userid`, `details`) VALUES (42, 'lorem')
   $this->connectionPool
       ->getConnectionForTable('sys_log')
       ->insert(
           'sys_log',
           [
               'userid' => (int)$userId,
               'details' => (string)$details,
           ],
           [
               Connection::PARAM_INT,
               Connection::PARAM_STR,
           ]
       );

   Copied!

   Read how to instantiate a connection with the connection pool. See available parameter types.

insert() returns the number of affected rows. Guess what? That is the number 1 ... If something goes wrong, a \Doctrine\DBAL\DBALException is thrown.

bulkInsert()

This method insert multiple rows at once:

// use TYPO3\CMS\Core\Database\Connection;
$connection = $this->connectionPool->getConnectionForTable('sys_log');
$connection->bulkInsert(
    'sys_log',
    [
        [(int)$userId, (string)$details1],
        [(int)$userId, (string)$details2],
    ],
    [
        'userid',
        'details',
    ],
    [
        Connection::PARAM_INT,
        Connection::PARAM_STR,
    ]
);

Read how to instantiate a connection with the connection pool. See available parameter types.

Arguments of the bulkInsert() method:

1. The name of the table the row should be inserted. Required.
2. An array of the values to be inserted. Required.
3. An array containing the column names of the data which should be inserted. Optional.
4. Specify how single values are quoted. Similar to insert(); if omitted, everything will be quoted to strings. Optional.

The number of inserted rows are returned. If something goes wrong, a \Doctrine\DBAL\DBALException is thrown.

update()

Create an UPDATE statement and execute it. The example from FAL's ResourceStorage sets a storage to offline:

// use TYPO3\CMS\Core\Database\Connection;
// UPDATE `sys_file_storage` SET `is_online` = 0 WHERE `uid` = '42'
$this->connectionPool
    ->getConnectionForTable('sys_file_storage')
    ->update(
        'sys_file_storage',
        ['is_online' => 0],
        ['uid' => (int)$this->getUid()],
        [Connection::PARAM_INT]
    );

Read how to instantiate a connection with the connection pool. See available parameter types.

Arguments of the update() method:

1. The name of the table to update. Required.
2. An associative array containing field/value pairs to be updated. The key is a field name, the value is the value. In SQL they are mapped to the SET keyword. Required.
3. The update criteria as an array of key/value pairs. The key is the field name, the value is the value. In SQL they are mapped in a WHERE keyword combined with AND. Required.
4. Specify how single values are quoted. Similar to insert(); if omitted, everything will be quoted to strings. Optional.

The method returns the number of updated rows. If something goes wrong, a \Doctrine\DBAL\DBALException is thrown.

delete()

Execute a DELETE query using equal conditions in WHERE, example from BackendUtility, to mark rows as no longer locked by a user:

// use TYPO3\CMS\Core\Database\Connection;
// DELETE FROM `sys_lockedrecords` WHERE `userid` = 42
$this->connectionPool
    ->getConnectionForTable('sys_lockedrecords')
    ->delete(
        'sys_lockedrecords',
        ['userid' => (int)42],
        [Connection::PARAM_INT]
    );

Read how to instantiate a connection with the connection pool. See available parameter types.

Arguments of the delete() method:

1. The name of the table. Required.
2. The delete criteria as an array of key/value pairs. The key is the field name, the value is the value. In SQL they are mapped in a WHERE keyword combined with AND. Required.
3. Specify how single values are quoted. Similar to insert(); if omitted, everything will be quoted to strings. Optional.

The method returns the number of deleted rows. If something goes wrong, a \Doctrine\DBAL\DBALException is thrown.

truncate()

This method empties a table, removing all rows. It is usually much faster than a delete() of all rows. This typically resets "auto increment primary keys" to zero. Use with care:

// TRUNCATE `cache_treelist`
$this->connectionPool
    ->getConnectionForTable('cache_treelist')
    ->truncate('cache_treelist');

Read how to instantiate a connection with the connection pool.

The argument is the name of the table to be truncated. If something goes wrong, a \Doctrine\DBAL\DBALException is thrown.

count()

This method executes a COUNT query. Again, this becomes useful when very simple COUNT statements are to be executed. The example below returns the number of active rows from the table tt_content whose bodytext field set to lorem:

// SELECT COUNT(*)
// FROM `tt_content`
// WHERE
//     (`bodytext` = 'lorem')
//     AND (
//         (`tt_content`.`deleted` = 0)
//         AND (`tt_content`.`hidden` = 0)
//         AND (`tt_content`.`starttime` <= 1475621940)
//         AND ((`tt_content`.`endtime` = 0) OR (`tt_content`.`endtime` > 1475621940))
//     )
$connection = $this->connectionPool->getConnectionForTable('tt_content');
$rowCount = $connection->count(
    '*',
    'tt_content',
    ['bodytext' => 'lorem']
);

Read how to instantiate a connection with the connection pool.

Arguments of the count() method:

1. The field to count, usually * or uid. Required.
2. The name of the table. Required.
3. The select criteria as an array of key/value pairs. The key is the field name, the value is the value. In SQL they are mapped in a WHERE keyword combined with AND. Required.

The method returns the counted rows.

Remarks:

• Connection::count() returns the number directly as an integer, unlike the method of the query builder it is not necessary to call ->fetchColumns(0) or similar.
• The third argument expects all WHERE values to be strings, each single expression is combined with AND.
• The restriction builder kicks in and adds additional WHERE conditions based on TCA settings.
• Field names and values are quoted automatically.
• If anything more complex than a simple equal condition on WHERE is needed, the query builder methods are the better choice: next to select(), the ->count() query is often the least useful method of the Connection object.

select()

This method creates and executes a simple SELECT query based on equal conditions. Its usage is limited, the restriction builder kicks in and key/value pairs are automatically quoted:

// SELECT `entry_key`, `entry_value`
//     FROM `sys_registry`
//     WHERE `entry_namespace` = 'my_extension'
$resultRows = $this->connectionPool
  ->getConnectionForTable('sys_registry')
  ->select(
     ['entry_key', 'entry_value'],
     'sys_registry',
     ['entry_namespace' => 'my_extension']
  );

Read how to instantiate a connection with the connection pool.

Arguments of the select() method:

1. The columns of the table which to select as an array. Required.
2. The name of the table. Required.
3. The select criteria as an array of key/value pairs. The key is the field name, the value is the value. In SQL they are mapped in a WHERE keyword combined with AND. Optional.
4. The columns to group the results by as an array. In SQL they are mapped in a GROUP BY keyword. Optional.
5. An associative array of column name/sort directions pairs. In SQL they are mapped in an ORDER BY keyword. Optional.
6. The maximum number of rows to return. In SQL it is mapped in a LIMIT keyword. Optional.
7. The first result row to select (when used the maximum number of rows). In SQL it is mapped in an OFFSET keyword. Optional.

In contrast to the other short-hand methods, ->select() returns a Result object ready for ->fetchAssociative() to get single rows or for ->fetchAllAssociative() to get all rows at once.

Remarks:

• For non-trivial SELECT queries it is often better to switch to the according method of the query builder object.
• The restriction builder adds default WHERE restrictions. If these restrictions do not match the query requirements, it is necessary to switch to the QueryBuilder->select() method for fine-grained WHERE manipulation.

lastInsertId()

This method returns the uid of the last insert() statement. This is useful if the id is to be used directly afterwards:

$connection = $this->connectionPool->getConnectionForTable('pages');
$connection->insert(
    'pages',
    [
        'pid' => 0,
        'title' => 'Home',
    ]
);
$pageUid = (int)$connection->lastInsertId('pages');

Read how to instantiate a connection with the connection pool.

Remarks:

• ->lastInsertId($tableName) takes the table name as first argument. Although it is optional, you should always specify the table name for Doctrine DBAL compatibility with engines like PostgreSQL.
• If the name of the auto increment field is not uid, the second argument must be specified with the name of that field. For simple TYPO3 tables, uid is fine and the argument can be omitted.

createQueryBuilder()

The query builder should not be reused for multiple different queries. However, sometimes it is convenient to first fetch a connection object for a specific table and execute a simple query, and later create a query builder for a more complex query from that connection object. The usefulness of this method is limited, however, and at the time of writing no good example could be found in the Core.

The method can also be useful in loops to save some precious code characters:

$connection = $this->connection->getConnectionForTable($myTable);
foreach ($someList as $aListValue) {
    $myResult = $connection->createQueryBuilder
        ->select('something')
        ->from('whatever')
        ->where(...)
        ->executeQuery()
        ->fetchAllAssociative();
}

Read how to instantiate a connection with the connection pool.