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.

Setting Default Database 

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 array $default = [
        'DSN'      => '',
        'hostname' => 'localhost',
        'username' => 'root',
        'password' => '',
        'database' => 'database_name',
        'DBDriver' => 'MySQLi',
        'DBPrefix' => '',
        'pConnect' => false,
        'DBDebug'  => true,
        'charset'  => 'utf8mb4',
        'DBCollat' => 'utf8mb4_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 the writable folder. If you want to change the location, you must set the full path to the new folder (e.g., ‘database’ => WRITEPATH . ‘db/database_name.db’).

DSN 

Some database drivers (such as Postgre, OCI8) requires a full DSN (Data Source Name) string to connect. But 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.

If you specify a DSN, you should use the 'DSN' configuration setting, as if you’re using the driver’s underlying native PHP extension, like this:

    // OCI8
    public array $default = [
        'DSN' => '//localhost/XE',
        // ...
    ];

DSN in Universal Manner

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

    public array $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:

    // MySQLi
    public array $default = [
        'DSN' => 'MySQLi://username:password@hostname:3306/database?charset=utf8mb4&DBCollat=utf8mb4_general_ci',
        // ...
    ];

    // Postgre
    public array $default = [
        'DSN' => 'Postgre://username:password@hostname:5432/database?charset=utf8&connect_timeout=5&sslmode=require',
        // ...
    ];

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

namespace Config;

use CodeIgniter\Database\Config;

class Database extends Config
{
    // ...

    public array $default = [
        // ...
        'failover' => [
            [
                'hostname' => 'localhost1',
                'username' => '',
                'password' => '',
                'database' => '',
                'DBDriver' => 'MySQLi',
                'DBPrefix' => '',
                'pConnect' => true,
                'DBDebug'  => true,
                'charset'  => 'utf8mb4',
                'DBCollat' => 'utf8mb4_general_ci',
                'swapPre'  => '',
                'encrypt'  => false,
                'compress' => false,
                'strictOn' => false,
            ],
            [
                'hostname' => 'localhost2',
                'username' => '',
                'password' => '',
                'database' => '',
                'DBDriver' => 'MySQLi',
                'DBPrefix' => '',
                'pConnect' => true,
                'DBDebug'  => true,
                'charset'  => 'utf8mb4',
                'DBCollat' => 'utf8mb4_general_ci',
                'swapPre'  => '',
                'encrypt'  => false,
                'compress' => false,
                'strictOn' => false,
            ],
        ],
        // ...
    ];

    // ...
}

You can specify as many failovers as you like.

Setting Multiple Databases 

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 array $test = [
        'DSN'      => '',
        'hostname' => 'localhost',
        'username' => 'root',
        'password' => '',
        'database' => 'database_name',
        'DBDriver' => 'MySQLi',
        'DBPrefix' => '',
        'pConnect' => true,
        'DBDebug'  => true,
        'charset'  => 'utf8mb4',
        'DBCollat' => 'utf8mb4_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

namespace Config;

use CodeIgniter\Database\Config;

class Database extends Config
{
    // ...

    public string $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.

Changing Databases Automatically 

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;

/**
 * Database Configuration
 */
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 follow this format, where default is the group name:

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

But you cannot add a new property by setting environment variables, nor change a scalar value to an array. See Environment Variables as Replacements for Data for details.

So if you want to use SSL with MySQL, you need a hack. For example, set the array values as a JSON string in your .env file:

database.default.encrypt = {"ssl_verify":true,"ssl_ca":"/var/www/html/BaltimoreCyberTrustRoot.crt.pem"}

and decode it in the constructor in the Config class:

<?php

namespace Config;

use CodeIgniter\Database\Config;

/**
 * Database Configuration
 */
class Database extends Config
{
    // ...

    public function __construct()
    {
        // ...

        $array = json_decode($this->default['encrypt'], true);
        if (is_array($array)) {
            $this->default['encrypt'] = $array;
        }
    }
}

Description of Values 

Config Name	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 table and column names. Since v4.5.0, database names with dots are supported.
DBDriver	The database driver name. The case must match the driver name. You can set a fully qualified classname to use your custom driver. Supported drivers: `MySQLi`, `Postgre`, `SQLite3`, `SQLSRV`, and `OCI8`.
DBPrefix	An optional table prefix which will be 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 to throw exceptions when database errors occur.
charset	The character set used in communicating with the database.
DBCollat	(`MySQLi` only) The character collation used in communicating with the database.
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	(`Postgre` and `SQLSRV` only) The database schema, default value varies by driver.
encrypt	(`MySQLi` and `SQLSRV` only) Whether to use an encrypted connection. See MySQLi encrypt for `MySQLi` settings. `SQLSRV` driver accepts true/false.
compress	(`MySQLi` only) Whether to use client compression.
strictOn	(`MySQLi` only) true/false (boolean) - Whether to force “Strict Mode” connections, good for ensuring strict SQL while developing an application.
port	The database port number - Empty string `''` for default port (or dynamic port with `SQLSRV`).
foreignKeys	(`SQLite3` only) true/false (boolean) - Whether to enable Foreign Key constraint. Important SQLite3 Foreign Key constraint is disabled by default. See SQLite documentation. To enforce Foreign Key constraint, set this config item to true.
busyTimeout	(`SQLite3` only) milliseconds (int) - Sleeps for a specified amount of time when a table is locked.
numberNative	(`MySQLi` only) true/false (boolean) - Whether to enable MYSQLI_OPT_INT_AND_FLOAT_NATIVE.
dateFormat	The default date/time formats as PHP’s DateTime format. * `date` - date format * `datetime` - date and time format * `datetime-ms` - date and time with millisecond format * `datetime-us` - date and time with microsecond format * `time` - time format This can be used since v4.5.0, and you can get the value, e.g., `$db->dateFormat['datetime']`. Currently, the database drivers do not use these values directly, but Model uses them.

Note

Depending on what database driver you are using (MySQLi, Postgre, 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.

MySQLi 

hostname 

Configuring a Socket Connection

To connect to a MySQL server over a filesystem socket, the path to the socket should be specified in the 'hostname' setting. CodeIgniter’s MySQLi driver will notice this and configure the connection properly.

    // MySQLi over a socket
    public array $default = [
        // ...
        'hostname' => '/cloudsql/toolbox-tests:europe-north1:toolbox-db',
        // ...
        'DBDriver' => 'MySQLi',
        // ...
    ];

encrypt 

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 (boolean) - Whether to verify the server certificate or not