Database Connection Settings

Craft supports several database connection settings that give you control over how Craft connects to the database.

Ultimately, database connection settings must be set from config/db.php, but we recommend you initially set them as environment variables (such as in your .env file), and then pull the environment variable value into config/db.php using getenv() (opens new window).

For example, in a new Craft 3 project, your .env file should define these environment variables:

ENVIRONMENT="dev"
SECURITY_KEY=""
DB_DRIVER="mysql"
DB_SERVER="<host>"
DB_PORT="<port>"
DB_DATABASE="<dbname>"
DB_USER="root"
DB_PASSWORD=""
DB_SCHEMA="public"
DB_TABLE_PREFIX=""

The variables that start with DB_ are database connection settings, and they get pulled into config/db.php like this:

return [
    'driver' => getenv('DB_DRIVER'),
    'server' => getenv('DB_SERVER'),
    'port' => getenv('DB_PORT'),
    'database' => getenv('DB_DATABASE'),
    'user' => getenv('DB_USER'),
    'password' => getenv('DB_PASSWORD'),
    'schema' => getenv('DB_SCHEMA'),
    'tablePrefix' => getenv('DB_TABLE_PREFIX'),
];

You may also provide a DB_DSN environment variable. If defined, Craft will use that.

We recommend this environment variable approach for two reasons:

It keeps sensitive information out of your project’s codebase. (.env files should never be shared or committed to Git.)
It makes collaborating with other developers easier, as each developer can define their own settings without overwriting someone else’s settings.

Here’s the full list of database connection settings that Craft supports:

# `attributes`

Allowed types: array (opens new window)
Default value: []
Defined by: DbConfig::$attributes (opens new window)

An array of key => value pairs of PDO attributes to pass into the PDO constructor.

For example, when using the MySQL PDO driver (opens new window), if you wanted to enable a SSL database connection (assuming SSL is enabled in MySQL (opens new window) and 'user' can connect via SSL, you’d set these:

[
    PDO::MYSQL_ATTR_SSL_KEY    => '/path/to/my/client-key.pem',
    PDO::MYSQL_ATTR_SSL_CERT   => '/path/to/my/client-cert.pem',
    PDO::MYSQL_ATTR_SSL_CA     => '/path/to/my/ca-cert.pem',
],

# `charset`

Allowed types: string (opens new window)
Default value: 'utf8'
Defined by: DbConfig::$charset (opens new window)

The charset to use when creating tables.

You can change the character set and collation across all existing database tables using this terminal command:

> php craft db/convert-charset

# `collation`

Allowed types: string (opens new window), null (opens new window)
Default value: null
Defined by: DbConfig::$collation (opens new window)
Since: 3.6.4

The collation to use when creating tables.

This is only used by MySQL. If null, the charset’s (opens new window) default collation will be used.

Charset	Default collation
`utf8`	`utf8_general_ci`
`utf8mb4`	`utf8mb4_0900_ai_ci`

You can change the character set and collation across all existing database tables using this terminal command:

> php craft db/convert-charset

# `database`

Allowed types: string (opens new window), null (opens new window)
Default value: null
Defined by: DbConfig::$database (opens new window)

The name of the database to select.

# `driver`

Allowed types: string (opens new window), null (opens new window)
Default value: null
Defined by: DbConfig::$driver (opens new window)

The database driver to use. Either mysql for MySQL or pgsql for PostgreSQL.

# `dsn`

Allowed types: string (opens new window), null (opens new window)
Default value: null
Defined by: DbConfig::$dsn (opens new window)

The Data Source Name (“DSN”) that tells Craft how to connect to the database.

DSNs should begin with a driver prefix (mysql: or pgsql:), followed by driver-specific parameters. For example, mysql:host=127.0.0.1;port=3306;dbname=acme_corp.

MySQL parameters: https://php.net/manual/en/ref.pdo-mysql.connection.php (opens new window)
PostgreSQL parameters: https://php.net/manual/en/ref.pdo-pgsql.connection.php (opens new window)

# `password`

Allowed types: string (opens new window)
Default value: ''
Defined by: DbConfig::$password (opens new window)

The database password to connect with.

# `port`

Allowed types: integer (opens new window), null (opens new window)
Default value: null
Defined by: DbConfig::$port (opens new window)

The database server port. Defaults to 3306 for MySQL and 5432 for PostgreSQL.

# `schema`

Allowed types: string (opens new window)
Default value: 'public'
Defined by: DbConfig::$schema (opens new window)

The schema that Postgres is configured to use by default (PostgreSQL only).

To force Craft to use the specified schema regardless of PostgreSQL’s search_path setting, you must enable the setSchemaOnConnect (opens new window) setting.

# `server`

Allowed types: string (opens new window), null (opens new window)
Default value: null
Defined by: DbConfig::$server (opens new window)

The database server name or IP address. Usually localhost or 127.0.0.1.

# `setSchemaOnConnect`

Allowed types: boolean (opens new window)
Default value: false
Defined by: DbConfig::$setSchemaOnConnect (opens new window)
Since: 3.7.27

Whether the schema (opens new window) should be explicitly used for database queries (PostgreSQL only).

This will cause an extra SET search_path SQL query to be executed per database connection. Ideally, PostgreSQL’s search_path setting should be configured to prioritize the desired schema.

# `tablePrefix`

Allowed types: string (opens new window)
Default value: ''
Defined by: DbConfig::$tablePrefix (opens new window)

If you’re sharing Craft installs in a single database (MySQL) or a single database and using a shared schema (PostgreSQL), you can set a table prefix here to avoid per-install table naming conflicts. This can be no more than 5 characters, and must be all lowercase.

# `unixSocket`

Allowed types: string (opens new window), null (opens new window)
Default value: null
Defined by: DbConfig::$unixSocket (opens new window)

MySQL only. If this is set, the CLI connection string (used for yiic) will connect to the Unix socket instead of the server and port. If this is specified, then server and port settings are ignored.

# `url`

Allowed types: string (opens new window), null (opens new window)
Default value: null
Defined by: DbConfig::$url (opens new window)

The database connection URL, if one was provided by your hosting environment.

If this is set, the values for driver (opens new window), user (opens new window), database (opens new window), server (opens new window), port (opens new window), and database (opens new window) will be extracted from it.

# `useUnbufferedConnections`

Allowed types: boolean (opens new window)
Default value: false
Defined by: DbConfig::$useUnbufferedConnections (opens new window)
Since: 3.7.0

Whether batched queries should be executed on a separate, unbuffered database connection.

This setting only applies to MySQL. It can be enabled when working with high volume content, to prevent PHP from running out of memory when querying too much data at once. (See https://www.yiiframework.com/doc/guide/2.0/en/db-query-builder#batch-query-mysql (opens new window) for an explanation of MySQL’s batch query limitations.)

# `user`

Allowed types: string (opens new window)
Default value: 'root'
Defined by: DbConfig::$user (opens new window)

The database username to connect with.

Database Connection Settings

# attributes

# charset

# collation

# database

# driver

# dsn

# password

# port

# schema

# server

# setSchemaOnConnect

# tablePrefix

# unixSocket

# url

# useUnbufferedConnections

# user

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# `attributes`

# `charset`

# `collation`

# `database`

# `driver`

# `dsn`

# `password`

# `port`

# `schema`

# `server`

# `setSchemaOnConnect`

# `tablePrefix`

# `unixSocket`

# `url`

# `useUnbufferedConnections`

# `user`