Question

我如何在下面选择的两行之间交换operator_id？

即。 id=@job_offer_id的operator_id成为id=@job_received_id的operator_id，反之亦然。

query += "SELECT operator_id FROM booking WHERE id=@job_offer_id;" +
         "SELECT operator_id FROM booking WHERE id=@job_received_id";

我在这里包含了一个小提琴：http://sqlfiddle.com/#!9/cdc53/4

Answer 1

尝试自我加入

update booking as o join booking as r
set o.operator_id = r.operator_id, r.operator_id = o.operator_id
where o.id = 2 and r.id = 3;

像这样

Answer 2

尝试将其保存在变量上并再次将其用于其他查询;

/* SELECT operator_id FROM booking WHERE id=@job_offer_id; */
SELECT operator_id INTO @job_offer_id FROM booking WHERE id="2";
SELECT operator_id FROM booking WHERE id=@job_offer_id ;

/* SELECT operator_id FROM booking WHERE id=@job_received_id; */
SELECT operator_id INTO @job_received_id FROM booking WHERE id="3";
SELECT operator_id FROM booking WHERE id=@job_received_id ;

在SQL语句中切换两行的值

2 个答案: