PDO::__construct

Artikel
11/18/2022

Creates a connection to a SQL Server database.

Syntax

  
PDO::__construct($dsn [,$username [,$password [,$driver_options ]]] )

Parameters

$dsn: A string that contains the prefix name (always sqlsrv), a colon, and the Server keyword. For example, "sqlsrv:server=(local)". You can optionally specify other connection keywords. See Connection Options for a description of the Server keyword and the other connection keywords. The entire $dsn is in quotation marks, so each connection keyword should not be individually quoted.

$username: Optional. A string that contains the user's name. To connect using SQL Server Authentication, specify the login ID. To connect using Windows Authentication, specify "".

$password: Optional. A string that contains the user's password. To connect using SQL Server Authentication, specify the password. To connect using Windows Authentication, specify "".

$driver_options: Optional. You can specify PDO Driver Manager attributes, and Microsoft Drivers for PHP for SQL Server specific driver attributes -- PDO::SQLSRV_ATTR_ENCODING, PDO::SQLSRV_ATTR_DIRECT_QUERY. An invalid attribute does not generate an exception. Invalid attributes generate exceptions when specified with PDO::setAttribute.

Return Value

Returns a PDO object. If failure, returns a PDOException object.

Exceptions

PDOException

Remarks

You can close a connection object by setting the instance to null.

After a connection, PDO::errorCode displays 01000 instead of 00000.

If PDO::__construct fails for any reason, an exception is thrown, even if PDO::ATTR_ERRMODE is set to PDO::ERRMODE_SILENT.

Support for PDO was added in version 2.0 of the Microsoft Drivers for PHP for SQL Server.

Example with database

This example shows how to connect to a server using Windows Authentication, and specify a database.

<?php  
   $c = new PDO( "sqlsrv:Server=(local) ; Database = AdventureWorks ", "", "", array(PDO::SQLSRV_ATTR_DIRECT_QUERY => true));   
  
   $query = 'SELECT * FROM Person.ContactType';   
   $stmt = $c->query( $query );   
   while ( $row = $stmt->fetch( PDO::FETCH_ASSOC ) ) {   
      print_r( $row );   
   }  
   $c = null;   
?>

Example without database

This example shows how to connect to a server, specifying the database later.

<?php  
   $c = new PDO( "sqlsrv:server=(local)");  
  
   $c->exec( "USE AdventureWorks2022" );  
   $query = 'SELECT * FROM Person.ContactType';  
   $stmt = $c->query( $query );  
   while ( $row = $stmt->fetch( PDO::FETCH_ASSOC ) ){  
      print_r( $row );  
   }  
   $c = null;  
?>

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