(PHP 8 >= 8.4.0)
PDO::connect — Connect to a database and return a PDO subclass for drivers that support it
$dsn
,
$username
=
null
,
$password
=
null
,
$options
=
null
Creates an instance of a PDO subclass for the database being connection if it exists, otherwise return a generic PDO instance.
dsn
The Data Source Name, or DSN, contains the information required to connect to the database.
In general, a DSN consists of the PDO driver name, followed by a colon, followed by the PDO driver-specific connection syntax. Further information is available from the PDO driver-specific documentation .
The
dsn
parameter suppors three
different methods of specifying the argumens required to create
a database connection:
dsn
contains the full DSN.
dsn
consists of
uri:
followed by a URI that defines the location of a file containing
the DSN string. The URI can specify a local file or a remote URL.
uri:file:///path/to/dsnfile
dsn
consists of a name
name
that mapps to
pdo.dsn.
in
php.ini
defining the DSN string.
name
Note :
The alias must be defined in php.ini , and not .htaccess or httpd.conf
username
The user name for the DSN string. This parameter is optional for some PDO drivers.
password
The password for the DSN string. This parameter is optional for some PDO drivers.
options
A key=>value array of driver-specific connection options.
Returns an instance of a PDO subclass for the corresponding PDO driver if it exists, or a generic PDO instance.
A
PDOException
is thrown if the attempt
to connect to the requested database fails,
regardless of which
PDO::ATTR_ERRMODE
is currently set.