$command = Admin::find()
-> select('tbl_user.*,tbl_admin.*')
-> join('LEFT JOIN','tbl_user','tbl_user.admin_id=tbl_admin.id')
-> asArray()
-> all();
等同于
$command = ( new \yii\db\Query())
-> select('tbl_user.*,tbl_admin.*')
-> from( 'admin' )
-> join('LEFT JOIN','tbl_user','tbl_user.admin_id = tbl_admin.id')
-> asArray()
-> all();