MySQL PDO Driver (PDO_MYSQL)

Introduzione

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.

Avviso

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.

Nota:

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).

Installazione

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::ATTR_SSL_*, 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.

Costanti predefinite

Le costanti qui sotto sono definite da questo driver, e sono disponibili solo quanto l'estensione è stata o compilata nel PHP o caricata dinamicamente a runtime. In aggiunta, queste costanti specifiche del driver dovrebbero essere usate solo se si sta usando il driver stesso. Utilizzare attributi specifici di mysql con il driver postgres può portare a risultati imprevedibili. PDO::getAttribute() può essere usata per ottenere l'attributo PDO_ATTR_DRIVER_NAME per identificare il driver, se il codice può funzionare con driver differenti.

PDO::MYSQL_ATTR_USE_BUFFERED_QUERY (int)
Alias di Pdo\Mysql::ATTR_USE_BUFFERED_QUERY
PDO::MYSQL_ATTR_LOCAL_INFILE (int)
Alias di Pdo\Mysql::ATTR_LOCAL_INFILE
PDO::MYSQL_ATTR_LOCAL_INFILE_DIRECTORY (int)
Alias di Pdo\Mysql::ATTR_LOCAL_INFILE_DIRECTORY. Available as of PHP 8.1.0.
PDO::MYSQL_ATTR_INIT_COMMAND (int)
Alias di Pdo\Mysql::ATTR_INIT_COMMAND
PDO::MYSQL_ATTR_READ_DEFAULT_FILE (int)
Alias di Pdo\Mysql::ATTR_READ_DEFAULT_FILE
PDO::MYSQL_ATTR_READ_DEFAULT_GROUP (int)
Alias di Pdo\Mysql::ATTR_READ_DEFAULT_GROUP
PDO::MYSQL_ATTR_MAX_BUFFER_SIZE (int)
Alias di Pdo\Mysql::ATTR_MAX_BUFFER_SIZE
PDO::MYSQL_ATTR_DIRECT_QUERY (int)
Alias di PDO::ATTR_EMULATE_PREPARES
PDO::MYSQL_ATTR_FOUND_ROWS (int)
Alias di Pdo\Mysql::ATTR_FOUND_ROWS
PDO::MYSQL_ATTR_IGNORE_SPACE (int)
Alias di Pdo\Mysql::ATTR_IGNORE_SPACE
PDO::MYSQL_ATTR_COMPRESS (int)
Alias di Pdo\Mysql::ATTR_COMPRESS
PDO::MYSQL_ATTR_SERVER_PUBLIC_KEY (int)
Alias di Pdo\Mysql::ATTR_SERVER_PUBLIC_KEY
PDO::MYSQL_ATTR_SSL_CA (int)
Alias di Pdo\Mysql::ATTR_SSL_CA
PDO::MYSQL_ATTR_SSL_CAPATH (int)
Alias di Pdo\Mysql::ATTR_SSL_CAPATH
PDO::MYSQL_ATTR_SSL_CERT (int)
Alias di Pdo\Mysql::ATTR_SSL_CERT
PDO::MYSQL_ATTR_SSL_CIPHER (int)
Alias di Pdo\Mysql::ATTR_SSL_CIPHER
PDO::MYSQL_ATTR_SSL_KEY (int)
Alias di Pdo\Mysql::ATTR_SSL_KEY
PDO::MYSQL_ATTR_SSL_VERIFY_SERVER_CERT (int)
Alias di Pdo\Mysql::ATTR_SSL_VERIFY_SERVER_CERT Available as of PHP 7.0.18 and PHP 7.1.4.
PDO::MYSQL_ATTR_MULTI_STATEMENTS (int)
Alias di Pdo\Mysql::ATTR_MULTI_STATEMENTS

Configurazione di Runtime

Il comportamento di queste funzioni è influenzato dalle impostazioni di php.ini.

PDO_MYSQL Configuration Options
Nome Default Modificabile
pdo_mysql.default_socket "/tmp/mysql.sock" INI_SYSTEM
pdo_mysql.debug NULL INI_SYSTEM
Per maggiori dettagli e definizioni sui modi INI_*, vedere Where a configuration setting may be set.

Breve descrizione dei parametri di configurazione.

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 bool

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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