Before this $builder, I want to select a database, what shall I do? I don't want to use raw SQL. Thanks!
$builder = $this->modelsManager->createBuilder()
->columns($cols)
->distinct(true)
->from($ZUC)
->leftJoin($ZU, "$ZU.user_id = $ZUC.user_id")
->leftJoin($ZSC, "$ZUC.subclass_id = $ZSC.subclass_id")
->leftJoin($ZC, "$ZC.class_id = $ZSC.class_id")
->leftJoin($ZCH, "$ZCH.order_no = $ZUC.order_no")
->where($conStr, $conArr)
->orderBy($order);