How to connect to POSTGRESQL in Codeigniter 3?

First enable Postgresql extension in php.ini

extension=php_pgsql.dll

You also can enable Postgresql extension for PDO as well.

extension=php_pdo_pgsql.dll

$db['default'] = array(    'port'   => 5432, # Add );

OR

$db['default'] = array(    'dsn'   => 'pgsql:host=localhost;port=5432;dbname=database_name',     'dbdriver' => 'pdo',);

Database-configuration in codeigniter.com

Tested with Codeigniter 4, PHP 7.3 and PostgreSQL 9.3.5:

1) Enable in your php.ini

extension=php_pgsql.dll

2) In app/Config/Database class override your $default property as follows:

/** * The default database connection. * * @var array */public $default = [    'DSN'      => '',    'hostname' => 'your_host',    'username' => 'your-user',    'password' => 'your-password',    'database' => 'your-database',    'DBDriver' => 'postgre',    'DBPrefix' => '',    'pConnect' => false,    'DBDebug'  => (ENVIRONMENT !== 'production'),    'cacheOn'  => false,    'cacheDir' => '',    'charset'  => 'utf8',    'DBCollat' => 'utf8_general_ci',    'swapPre'  => '',    'encrypt'  => false,    'compress' => false,    'strictOn' => false,    'failover' => [],    'port'     => 5432, //the default port ];

1. First enable these two extensions

   extension=php_pgsql.dllextension=php_pdo_pgsql.dll

2. Then restart apache
3. Add $db['default']['port'] = 5432 in database.php file with all other codes.