在SQL中使用Union执行UPDATE
发布时间:2020-12-12 07:44:35 所属栏目:MsSql教程 来源:网络整理
导读:如果我有这三个表(只是一个例子来学习UNION,这些不是真正的表): 表格及其列: Customer: id | name | order_statusOrder_Web:id | customer_id | order_filledOrder:id | customer_id | order_filled 我想在Order_Web表或使用Union的客户的Order表中填写订单
如果我有这三个表(只是一个例子来学习UNION,这些不是真正的表):
表格及其列: Customer: id | name | order_status Order_Web: id | customer_id | order_filled Order: id | customer_id | order_filled 我想在Order_Web表或使用Union的客户的Order表中填写订单时更新Customer表中的order_status: UPDATE c SET c.order_status = 1 FROM Customer AS c INNER JOIN Order_Web As ow ON c.id = ow.customer_id WHERE ow.order_filled = 1 UPDATE c SET c.order_status = 1 FROM Customer AS c INNER JOIN Order As o ON c.id = o.customer_id WHERE o.order_filled = 1 如何在order_web和订单上使用Union来组合这两个更新? 使用Microsoft SQL Server Management Studio 解决方法你不需要UINION – 用一对外连接替换内连接应该这样做:UPDATE c SET c.order_status = 1 FROM Customer AS c LEFT OUTER JOIN Order_Web As ow ON c.id = ow.customer_id LEFT OUTER JOIN Order As o ON c.id = o.customer_id WHERE ow.order_filled = 1 OR o.order_filled = 1 您还可以使用WHERE EXISTS,如下所示: UPDATE c SET c.order_status = 1 FROM Customer AS c WHERE EXISTS ( SELECT 1 FROM Order_Web As ow WHERE c.id = ow.customer_id AND ow.order_filled = 1 ) OR EXISTS ( SELECT 1 FROM Order As o WHERE c.id = o.customer_id AND o.order_filled = 1 ) 如果必须使用UNION,可以按如下方式执行: UPDATE c SET c.order_status = 1 FROM Customer AS c WHERE c.id in ( SELECT ow.id FROM Order_Web As ow WHERE ow.order_filled = 1 UNION SELECT o.id FROM Order As o WHERE o.order_filled = 1 ) 或者与JOIN相同的人: UPDATE c SET c.order_status = 1 FROM Customer AS c JOIN ( SELECT ow.id AS id FROM Order_Web As ow WHERE ow.order_filled = 1 UNION SELECT o.id AS id FROM Order As o WHERE o.order_filled = 1 ) AS ids ON ids.id = c.id (编辑:李大同) 【声明】本站内容均来自网络,其相关言论仅代表作者个人观点,不代表本站立场。若无意侵犯到您的权利,请及时与联系站长删除相关内容! |