Database Configuration

Note

See Supported Databases for currently supported database drivers.

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:password@hostname: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:password@hostname:3306/database?charset=utf8&DBCollat=utf8_general_ci',
    // ...
];

// Postgre
$default = [
    'DSN' => 'Postgre://username:password@hostname: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:

Name Config

Description

dsn

The DSN connect string (an all-in-one configuration sequence).

hostname

The hostname of your database server. Often this is ‘localhost’.

username

The username used to connect to the database. (SQLite3 does not use this.)

password

The password used to connect to the database. (SQLite3 does not use this.)

database

The name of the database you want to connect to.

Note

CodeIgniter doesn’t support dots (.) in the database, table, and column names.

DBDriver

The database driver name. e.g.,: MySQLi, Postgres, etc. The case must match the driver name

DBPrefix

An optional table prefix which will added to the table name when running Query Builder queries. This permits multiple CodeIgniter installations to share one database.

pConnect

true/false (boolean) - Whether to use a persistent connection.

DBDebug

true/false (boolean) - Whether database errors should be displayed.

charset

The character set used in communicating with the database.

DBCollat

The character collation used in communicating with the database (MySQLi only)

swapPre

A default table prefix that should be swapped with DBPrefix. This is useful for distributed applications where you might run manually written queries, and need the prefix to still be customizable by the end user.

schema

The database schema, default value varies by driver. (Used by Postgres and SQLSRV.)

encrypt

Whether or not to use an encrypted connection. SQLSRV driver accepts true/false MySQLi driver accepts an array with the following options: * ssl_key - Path to the private key file * ssl_cert - Path to the public key certificate file * ssl_ca - Path to the certificate authority file * ssl_capath - Path to a directory containing trusted CA certificates in PEM format * ssl_cipher - List of allowed ciphers to be used for the encryption, separated by colons (:) * ssl_verify - true/false; Whether to verify the server certificate or not (MySQLi only)

compress

Whether or not to use client compression (MySQLi only).

strictOn

true/false (boolean) - Whether to force “Strict Mode” connections, good for ensuring strict SQL while developing an application (MySQLi only).

port

The database port number.

foreignKeys

true/false (boolean) - Whether or not to enable Foreign Key constraint (SQLite3 only).

Important

SQLite3 Foreign Key constraint is disabled by default. See SQLite documentation. To enforce Foreign Key constraint, set this config item to true.

Note

Depending on what database driver you are using (MySQLi, Postgres, etc.) not all values will be needed. For example, when using SQLite3 you will not need to supply a username or password, and the database name will be the path to your database file.