Laravel 使用多个数据库连接

NECTION=mysql
DB_HOST=127.0.0.1
DB_PORT=3306
DB_DATABASE=database_name
DB_USERNAME=root
DB_PASSWORD=

DB_HOST_EXREND=127.0.0.1
DB_PORT_EXREND=3306
DB_DATABASE_EXREND=database_center
DB_USERNAME_EXREND=root
DB_PASSWORD_EXREND=

'mysql' => [
        'driver' => 'mysql',
        'host' => env('DB_HOST', 'localhost'),
        'port' => env('DB_PORT', '3306'),
        'database' => env('DB_DATABASE', 'forge'),
        'username' => env('DB_USERNAME', 'forge'),
        'password' => env('DB_PASSWORD', ''),
        'charset' => 'utf8',
        'collation' => 'utf8_unicode_ci',
        'prefix' => '',
        'strict' => false,
        'engine' => null,
],
'mysql_extend' => [
        'driver' => 'mysql',
        'host' => env('DB_HOST_EXREND', 'localhost'),
        'port' => env('DB_PORT_EXREND', '3306'),
        'database' => env('DB_DATABASE_EXRENDR', 'forge'),
        'username' => env('DB_USERNAME_EXREND', 'forge'),
        'password' => env('DB_PASSWORD_EXREND', ''),
        'charset' => 'utf8',
        'collation' => 'utf8_unicode_ci',
        'prefix' => '',
        'strict' => false,
        'engine' => null,
],

DB::connection("mysql_extend")->table("user")->find($id);

public $connection = 'mysql_extend';
public $table = "user";
User::find($id);