Database Techniques and PHP

 Connecting 

Once you have a DSN, create a connection to the database using the connect() method. This returns a database object you’ll use for tasks such as issuing queries and quoting parameters:

  $db = DB::connect(DSN [, options ]);

Theoptions  value can either be Boolean, indicating whether or not the connection is to be persistent, or an array of options settings. Theoptions  values are given in Table 8-2.

By default, the connection is not persistent and no debugging information is displayed. Permitted values foroptimizeare'performance'and'portability'. The default is'performance'. Here’s how to enable debugging and optimize for portability:

  $db = DB::connect($dsn, array('debug' => 1, 'optimize' => 'portability'));

Error Checking

PEAR DB methods return DB_ERROR if an error occurs. You can check for this with DB::isError():

  $db = DB::connect($datasource);
  if (DB::isError($db)) {
    die($db->getMessage());
  }

TheDB::isError()method returnstrueif an error occurred while working with the database object. If there was an error, the usual behavior is to stop the program and display the error message reported by thegetMessage()method. You can callgetMessage()on any PEAR DB object.