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MySQL Functions (PDO_MYSQL)
Introduction
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.
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.
Note:
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).
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 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.
Predefined Constants
The constants below are defined by
this driver, and will only be available when the extension has been either
compiled into PHP or dynamically loaded at runtime. In addition, these
driver-specific constants should only be used if you are using this driver.
Using driver-specific attributes with another driver may result in
unexpected behaviour. PDO::getAttribute may be used to
obtain the PDO::ATTR_DRIVER_NAME attribute to check the
driver, if your code can run against multiple drivers.
-
PDO::MYSQL_ATTR_USE_BUFFERED_QUERY
(bool)
-
By default all statements are executed in
buffered mode.
If this attribute is set to
false on a
PDO object, the MySQL driver will use the
unbuffered mode.
Example #1 Setting MySQL unbuffered mode
<?php
$pdo = new PDO("mysql:host=localhost;dbname=world", 'my_user', 'my_password');
$pdo->setAttribute(PDO::MYSQL_ATTR_USE_BUFFERED_QUERY, false);
$unbufferedResult = $pdo->query("SELECT Name FROM City");
foreach ($unbufferedResult as $row) {
echo $row['Name'] . PHP_EOL;
}
?>
-
PDO::MYSQL_ATTR_LOCAL_INFILE
(int)
-
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_LOCAL_INFILE_DIRECTORY
(string)
-
Allows restricting LOCAL DATA loading to files located in this designated
directory. Available as of PHP 8.1.0.
Note, this constant can only be used in the driver_options
array when constructing a new database handle.
-
PDO::MYSQL_ATTR_INIT_COMMAND
(string)
-
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
(int)
-
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
(int)
-
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
(int)
-
Maximum buffer size. Defaults to 1 MiB. This constant is not supported when
compiled against mysqlnd.
-
PDO::MYSQL_ATTR_DIRECT_QUERY
(int)
-
Perform direct queries, don't use prepared statements.
-
PDO::MYSQL_ATTR_FOUND_ROWS
(int)
-
Return the number of found (matched) rows, not the
number of changed rows.
-
PDO::MYSQL_ATTR_IGNORE_SPACE
(int)
-
Permit spaces after function names. Makes all functions
names reserved words.
-
PDO::MYSQL_ATTR_COMPRESS
(int)
-
Enable network communication compression.
-
PDO::MYSQL_ATTR_SSL_CA
(int)
-
The file path to the SSL certificate authority.
-
PDO::MYSQL_ATTR_SSL_CAPATH
(int)
-
The file path to the directory that contains the trusted SSL
CA certificates, which are stored in PEM format.
-
PDO::MYSQL_ATTR_SSL_CERT
(int)
-
The file path to the SSL certificate.
-
PDO::MYSQL_ATTR_SSL_CIPHER
(int)
-
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
-
PDO::MYSQL_ATTR_SSL_KEY
(int)
-
The file path to the SSL key.
-
PDO::MYSQL_ATTR_SSL_VERIFY_SERVER_CERT
(int)
-
Provides a way to disable verification of the server SSL certificate.
This option is available only with mysqlnd.
This exists as of PHP 7.0.18 and PHP 7.1.4.
-
PDO::MYSQL_ATTR_MULTI_STATEMENTS
(int)
-
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.
Runtime Configuration
The behaviour of these functions is affected by settings in php.ini.
For further details and definitions of the
INI_* modes, see the Where a configuration setting may be set.
Here's a short explanation of
the configuration directives.
-
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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