MySQL Functions (PDO_MYSQL)

简介

PDO_MYSQL is a driver that implements the PHP Data Objects (PDO) interface to enable access from PHP to MySQL 3.x, 4.x and 5.x databases.

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.

Warning

Beware: Some MySQL table types (storage engines) do not support transactions. When writing transactional database code using a table type that does not support transactions, MySQL will pretend that a transaction was initiated successfully. In addition, any DDL queries issued will implicitly commit any pending transactions.

安装

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.

更新日志
版本 说明
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.

预定义常量

下列常量由此驱动定义,且仅在扩展编译入 PHP 或在运行时动态载入时可用。另外,使用此驱动时,仅会使用这些驱动特定的常量。使用其他驱动的驱动特定的常量可能会导致不可预见的情况。如果代码可运行于多个驱动,PDO::getAttribute() 可被用于获取 PDO_ATTR_DRIVER_NAME 属性以检查驱动。

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.

Example #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.

自以下版本起 PHP 5.3.7.

PDO::MYSQL_ATTR_SSL_CAPATH (integer)

The file path to the directory that contains the trusted SSL CA certificates, which are stored in PEM format.

自以下版本起 PHP 5.3.7.

PDO::MYSQL_ATTR_SSL_CERT (integer)

The file path to the SSL certificate.

自以下版本起 PHP 5.3.7.

PDO::MYSQL_ATTR_SSL_CIPHER (integer)

A list of one or more permissible ciphers to use for SSL encryption, in a format understood by OpenSSL. For example: DHE-RSA-AES256-SHA:AES128-SHA

自以下版本起 PHP 5.3.7.

PDO::MYSQL_ATTR_SSL_KEY (integer)

The file path to the SSL key.

自以下版本起 PHP 5.3.7.

PDO::MYSQL_ATTR_MULTI_STATEMENTS (integer)

Disables multi query execution in both PDO::prepare() and PDO::query() when set to FALSE.

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

自以下版本起 PHP 5.5.21 and PHP 5.6.5.

运行时配置

这些函数的行为受 php.ini 中的设置影响。

PDO_MYSQL Configuration Options
名字 默认 可修改范围
pdo_mysql.default_socket "/tmp/mysql.sock" PHP_INI_SYSTEM
pdo_mysql.debug NULL PHP_INI_SYSTEM
有关 PHP_INI_* 样式的更多详情与定义,见 配置可被设定范围

这是配置指令的简短说明。

pdo_mysql.default_socket string

Sets a Unix domain socket. This value can either be set at compile time if a domain socket is found at configure. This ini setting is Unix only.

pdo_mysql.debug boolean

Enables debugging for PDO_MYSQL. This setting is only available when PDO_MYSQL is compiled against mysqlnd and in PDO debug mode.

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