PHP Cookbook

10.3. Connecting to a SQL Database

Problem

You want access to a SQL database.

Solution

Use the connect( ) method of PEAR DB:

require 'DB.php';

$dsn = 'mysql://david:foo!bar@localhost/test';

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

Discussion

To use PEAR DB, you must download it from PEAR at:

http://pear.php.net/package-info.php?package=DB

After loading the DB functions from DB.php, connect to the database with DB::connect( ), execute the query with $dbh->query( ) , and retrieve each row with $sth->fetchRow( ) . The Solution example connects to MySQL. To connect to Oracle instead, you just need to change $dsn. This variable holds the data source name (DSN), a string that specifies which database to connect to and how to connect to it. Here’s the value for Oracle:

$dsn = 'oci8://david:foo!bar@ORAINST';

For PostgreSQL, $dsn is:

$dsn = 'pgsql://david:foo!bar@unix(/tmp/.s.PGSQL.5432)/test';

The PostgreSQL DSN is a little more complicated because it specifies that the connection should be made using a local Unix socket (whose pathname is /tmp/.s.PGSQL.5432) instead of a TCP/IP connection. In general, the form of a data source name is:

               database_interface://user:password@hostname/database

The database_interface part of the DSN is the kind of database you’re using, such as Oracle, MySQL, etc. Currently, PEAR supports 10 database backends, as listed in Table 10-1.

Table 10-1. PEAR DB backends

Name	Database
fbsql	FrontBase
ibase	Interbase