简介
PDO_MYSQL is a driver that implements the PHP
Data Objects (PDO) interface
to enable access from PHP to MySQL databases.
PDO_MYSQL uses emulated prepares by default.
MySQL 8
When running a PHP version before 7.1.16, or PHP 7.2 before 7.2.4, set
MySQL 8 Server's default password plugin to mysql_native_password
or else you will see errors similar to
The server requested authentication method unknown to the client [caching_sha2_password]
even when caching_sha2_password is not used.
This is because MySQL 8 defaults to caching_sha2_password, a plugin that is
not recognized by the older PHP (mysqlnd) releases. Instead, change it by
setting default_authentication_plugin=mysql_native_password
in my.cnf. The caching_sha2_password
plugin is fully supported as of PHP 7.4.4. For older releases, the
mysql_xdevapi extension does
support it.
警告
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.
注意:
The MySQL driver does not properly support PDO::PARAM_INPUT_OUTPUT
via PDOStatement::bindParam(); while such parameters can be used,
they are not updated (i.e. the actual output is ignored).
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 that 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. 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.