MySQL Funktionen (PDO

Einführung

PDO_MYSQL ist ein Treiber welcher das PHP Data Objects (PDO) interface implementiert hat. Es ermöglicht den Zugriff von PHP auf MySQL 3.x, 4.x und 5.x Datenbanken.

PDO_MYSQL will take advantage of native prepared statement support present in MySQL 4.1 and higher. If you're using an older version of the mysql client libraries, PDO will emulate them for you.

Warnung

Vorsicht: Einige MySQL Tabellen Typen (storage engines), u.a. MyISAM, unterstützen keine Transaktionen. Wenn Transaktionen im PHP Code verwendet und auf nicht transaktionsfähige Tabellen verwendet werden, wird von MySQL eine erfolgreiche Rückmeldung betreffend der Transaktionsausführung kommen. Ausserdem werden einige DDL Queries eine implizit Übertragung der hängenden Transaktionen ausgeben.

Installation

The common Unix distributions include binary versions of PHP that can be installed. Although these binary versions are typically built with support for the MySQL extensions, the extension libraries themselves may need to be installed using an additional package. Check the package manager than comes with your chosen distribution for availability.

For example, on Ubuntu the php5-mysql package installs the ext/mysql, ext/mysqli, and PDO_MYSQL PHP extensions. On CentOS, the php-mysql package also installs these three PHP extensions.

Alternatively, you can compile this extension yourself. Building PHP from source allows you to specify the MySQL extensions you want to use, as well as your choice of client library for each extension.

When compiling, use --with-pdo-mysql[=DIR] to install the PDO MySQL extension, where the optional [=DIR] is the MySQL base library. As of PHP 5.4, mysqlnd is the default library. For details about choosing a library, see Choosing a MySQL library.

Optionally, the --with-mysql-sock[=DIR] sets to location to the MySQL unix socket pointer for all MySQL extensions, including PDO_MYSQL. If unspecified, the default locations are searched.

Optionally, the --with-zlib-dir[=DIR] is used to set the path to the libz install prefix.

$ ./configure --with-pdo-mysql --with-mysql-sock=/var/mysql/mysql.sock

SSL support is enabled using the appropriate PDO_MySQL constants, which is equivalent to calling the » MySQL C API function mysql_ssl_set(). Also, SSL cannot be enabled with PDO::setAttribute because the connection already exists. See also the MySQL documentation about » connecting to MySQL with SSL.

**Changelog**
Version	Beschreibung
5.4.0	mysqlnd became the default MySQL library when compiling PDO_MYSQL. Previously, libmysqlclient was the default MySQL library.
5.4.0	MySQL client libraries 4.1 and below are no longer supported.
5.3.9	Added SSL support with mysqlnd and OpenSSL.
5.3.7	Added SSL support with libmysqlclient and OpenSSL.

Vordefinierte Konstanten

Die folgenden Konstanten werden vom Treiber definiert und sind nur verfügbar, wenn die Extension entweder in PHP einkompiliert oder dynamisch zur Laufzeit geladen wurde. Weiterhin sind diese Konstanten treiberspezifisch und sollten nur mit diesem Treiber benutzt werden. MySQL-spezifische Attribute mit dem PostgreSQL Treiber zu nutzen, kann zu unerwarteten Ergebnissen führen. Kann Ihr Code mit verschiedenen Treibern arbeiten, so können Sie PDO::getAttribute() benutzen, um mit PDO_ATTR_DRIVER_NAME den aktuellen Treiber zu ermitteln.

PDO::MYSQL_ATTR_USE_BUFFERED_QUERY (integer)

If this attribute is set to TRUE on a PDOStatement, the MySQL driver will use the buffered versions of the MySQL API. If you're writing portable code, you should use PDOStatement::fetchAll() instead.

Beispiel #1 Forcing queries to be buffered in mysql


<?php
if ($db->getAttribute(PDO::ATTR_DRIVER_NAME) == 'mysql') {
    $stmt = $db->prepare('select * from foo',
        array(PDO::MYSQL_ATTR_USE_BUFFERED_QUERY => true));
} else {
    die("my application only works with mysql; I should use \$stmt->fetchAll() instead");
}
?>

PDO::MYSQL_ATTR_LOCAL_INFILE (integer)

Enable LOAD LOCAL INFILE.

Note, this constant can only be used in the driver_options array when constructing a new database handle.

PDO::MYSQL_ATTR_INIT_COMMAND (integer)

Command to execute when connecting to the MySQL server. Will automatically be re-executed when reconnecting.

Note, this constant can only be used in the driver_options array when constructing a new database handle.

PDO::MYSQL_ATTR_READ_DEFAULT_FILE (integer)

Read options from the named option file instead of from my.cnf. This option is not available if mysqlnd is used, because mysqlnd does not read the mysql configuration files.

PDO::MYSQL_ATTR_READ_DEFAULT_GROUP (integer)

Read options from the named group from my.cnf or the file specified with MYSQL_READ_DEFAULT_FILE. This option is not available if mysqlnd is used, because mysqlnd does not read the mysql configuration files.

PDO::MYSQL_ATTR_MAX_BUFFER_SIZE (integer)

Maximum buffer size. Defaults to 1 MiB. This constant is not supported when compiled against mysqlnd.

PDO::MYSQL_ATTR_DIRECT_QUERY (integer)

Perform direct queries, don't use prepared statements.

PDO::MYSQL_ATTR_FOUND_ROWS (integer)

Return the number of found (matched) rows, not the number of changed rows.

PDO::MYSQL_ATTR_IGNORE_SPACE (integer)

Permit spaces after function names. Makes all functions names reserved words.

PDO::MYSQL_ATTR_COMPRESS (integer)

Enable network communication compression. This is also supported when compiled against mysqlnd as of PHP 5.3.11.

PDO::MYSQL_ATTR_SSL_CA (integer)

The file path to the SSL certificate authority.