Database configuration file in php

Config File

CodeIgniter has a config file that lets you store your database connection values (username, password, database name, etc.). The config file is located at app/Config/Database.php. You can also set database connection values in the .env file. See below for more details.

The config settings are stored in a class property that is an array with this prototype:

<?php

namespace Config;

use CodeIgniter\Database\Config;

class Database extends Config
{
    public $default = [
        'DSN'      => '',
        'hostname' => 'localhost',
        'username' => 'root',
        'password' => '',
        'database' => 'database_name',
        'DBDriver' => 'MySQLi',
        'DBPrefix' => '',
        'pConnect' => true,
        'DBDebug'  => true,
        'charset'  => 'utf8',
        'DBCollat' => 'utf8_general_ci',
        'swapPre'  => '',
        'encrypt'  => false,
        'compress' => false,
        'strictOn' => false,
        'failover' => [],
        'port'     => 3306,
    ];

    // ...
}

The name of the class property is the connection name, and can be used while connecting to specify a group name.

Note

The default location of the SQLite3 database is in the writable folder. If you want to change the location, you must set the full path to the new folder.

DSN

Some database drivers (such as PDO, PostgreSQL, Oracle, ODBC) might require a full DSN string to be provided. If that is the case, you should use the ‘DSN’ configuration setting, as if you’re using the driver’s underlying native PHP extension, like this:

<?php

// PDO
$default = [
    'DSN' => 'pgsql:host=localhost;port=5432;dbname=database_name',
    // ...
];

// Oracle
$default = [
    'DSN' => '//localhost/XE',
    // ...
];

Note

If you do not specify a DSN string for a driver that requires it, CodeIgniter will try to build it with the rest of the provided settings.

You can also set a Data Source Name in universal manner (URL like). In that case DSNs must have this prototype:

<?php

$default = [
    'DSN' => 'DBDriver://username:[email protected]:port/database',
    // ...
];

To override default config values when connecting with a universal version of the DSN string, add the config variables as a query string:

<?php

// MySQLi
$default = [
    'DSN' => 'MySQLi://username:[email protected]:3306/database?charset=utf8&DBCollat=utf8_general_ci',
    // ...
];

// Postgre
$default = [
    'DSN' => 'Postgre://username:[email protected]:5432/database?charset=utf8&connect_timeout=5&sslmode=1',
    // ...
];

Note

If you provide a DSN string and it is missing some valid settings (e.g., the database character set), which are present in the rest of the configuration fields, CodeIgniter will append them.

Failovers

You can also specify failovers for the situation when the main connection cannot connect for some reason. These failovers can be specified by setting the failover for a connection like this:

<?php

$default['failover'] = [
    [
        'hostname' => 'localhost1',
        'username' => '',
        'password' => '',
        'database' => '',
        'DBDriver' => 'MySQLi',
        'DBPrefix' => '',
        'pConnect' => true,
        'DBDebug'  => true,
        'charset'  => 'utf8',
        'DBCollat' => 'utf8_general_ci',
        'swapPre'  => '',
        'encrypt'  => false,
        'compress' => false,
        'strictOn' => false,
    ],
    [
        'hostname' => 'localhost2',
        'username' => '',
        'password' => '',
        'database' => '',
        'DBDriver' => 'MySQLi',
        'DBPrefix' => '',
        'pConnect' => true,
        'DBDebug'  => true,
        'charset'  => 'utf8',
        'DBCollat' => 'utf8_general_ci',
        'swapPre'  => '',
        'encrypt'  => false,
        'compress' => false,
        'strictOn' => false,
    ],
];

You can specify as many failovers as you like.

You may optionally store multiple sets of connection values. If, for example, you run multiple environments (development, production, test, etc.) under a single installation, you can set up a connection group for each, then switch between groups as needed. For example, to set up a “test” environment you would do this:

<?php

namespace Config;

use CodeIgniter\Database\Config;

class Database extends Config
{
    public $test = [
        'DSN'      => '',
        'hostname' => 'localhost',
        'username' => 'root',
        'password' => '',
        'database' => 'database_name',
        'DBDriver' => 'MySQLi',
        'DBPrefix' => '',
        'pConnect' => true,
        'DBDebug'  => true,
        'charset'  => 'utf8',
        'DBCollat' => 'utf8_general_ci',
        'swapPre'  => '',
        'compress' => false,
        'encrypt'  => false,
        'strictOn' => false,
        'failover' => [],
    ];

    // ...
}

Then, to globally tell the system to use that group you would set this variable located in the config file:

<?php

$defaultGroup = 'test';

Note

The name ‘test’ is arbitrary. It can be anything you want. By default we’ve used the word “default” for the primary connection, but it too can be renamed to something more relevant to your project.

defaultGroup

You could modify the config file to detect the environment and automatically update the defaultGroup value to the correct one by adding the required logic within the class’ constructor:

<?php

namespace Config;

use CodeIgniter\Database\Config;

class Database extends Config
{
    public $development = [/* ... */];
    public $test        = [/* ... */];
    public $production  = [/* ... */];

    public function __construct()
    {
        $this->defaultGroup = ENVIRONMENT;
    }
}

Configuring with .env File

You can also save your configuration values within a .env file with the current server’s database settings. You only need to enter the values that change from what is in the default group’s configuration settings. The values should be name following this format, where default is the group name:

database.default.username = 'root';
database.default.password = '';
database.default.database = 'ci4';

Explanation of Values:

<?php

$default = [
    // ...
    'port' => 5432,
];

Note

Depending on what database platform you are using (MySQL, PostgreSQL, etc.) not all values will be needed. For example, when using SQLite you will not need to supply a username or password, and the database name will be the path to your database file. The information above assumes you are using MySQL.