Database Introduction

Introduction

Fuel offers a driver based database abstraction layer. At the time of writing supported drivers are MySQL, MySQLi and PDO. Aside from regular database interaction, fuel also comes with a DBUtil class to perform database operations such as creating databases, adding fields and much more.

Please note that not all features are supported by every driver.

Configuration

In order to begin working with databases, you must change the database settings. The global settings, that are valid for all your environments, are defined in APPPATH/config/db.php. You define environment specific database settings in the db.php located in the appropriate environment configuration folder. The two will be merged to form the complete database configuration.

Database configurations are formated like so: 

// a MySQL driver configuration
'development' => array(
	'type'           => 'mysqli',
	'connection'     => array(
		'hostname'       => 'localhost',
		'port'           => '3306',
		'database'       => 'fuel_db',
		'username'       => 'your_username',
		'password'       => 'y0uR_p@ssW0rd',
		'persistent'     => false,
		'compress'       => false,
	),
	'identifier'     => '`',
	'table_prefix'   => '',
	'charset'        => 'utf8',
	'enable_cache'   => true,
	'profiling'      => false,
	'readonly'       => false,
	'command'        => '',
),

// a PDO driver configuration, using PostgreSQL
'production' => array(
	'type'           => 'pdo',
	'connection'     => array(
		'dsn'            => 'pgsql:host=localhost;dbname=fuel_db',
		'username'       => 'your_username',
		'password'       => 'y0uR_p@ssW0rd',
		'persistent'     => false,
		'compress'       => false,
	),
	'identifier'     => '"',
	'table_prefix'   => '',
	'charset'        => 'utf8',
	'enable_cache'   => true,
	'profiling'      => false,
	'readonly'       => array('slave1', 'slave2', 'slave3'),
	'command'        => '',
),

'slave1' => array(
	// configuration of the first production readonly slave db
),

'slave2' => array(
	// configuration of the second production readonly slave db
),

'slave3' => array(
	// configuration of the third production readonly slave db
),

Please note that type is required for all connections.

All Config Settings

Setting Type Description
type string What type of connection to use. Can be mysql, mysqli or pdo.
connection array Connection settings array
connection.dsn string Connection DSN for PDO.
connection.username string Connection user.
connection.password string Connection password.
connection.persistent boolean Whether to initiate a persisten connection.
connection.compress boolean Whether to use client compression when using MySQL / MySQLi.
identifier string Delimiter used to quote identifiers.
table_prefix string Table prefix.
charset string Connection charset.
enable_cache boolean Whether to allow caching, will overwrite query cache settings on a connection basis.
profiling boolean Whether to add the connections queries to the profiler.
readonly array|false If you have a database in a master/slave setup, you can use this to define an array of slave connections, which will be used at random for read operations.
command string Optional SQL command to send to the database after a connection has been made. You can use this for example to change session mode settings.

Once you have your configuration in place, it's time to use it.