Question

我正在尝试删除与CombinableOrders无关联的所有Orders

我的尝试

DELETE 
 FROM CombinableOrders pr    
 WHERE NOT EXISTS(SELECT * FROM Orders cr WHERE pr.Id = cr.CombinableOrder_Id)

Sql server错误

Only one expression can be specified in the select list when the subquery is not introduced with EXISTS.

我知道这一定很简单

更新

我认为pr和cr导致了这个问题，并且sql在前一个语句中给了我一个错误

Answer 1

试试这个：

DELETE
    CombinableOrders 
FROM 
    CombinableOrders
WHERE 
    NOT EXISTS(SELECT 1 FROM Orders WHERE CombinableOrders.Id = Orders.CombinableOrder_Id)

Answer 2

试试这个：删除来自CombinableOrders pr
WHERE（（SELECT COUNT（*）FROM Orders cr WHERE pr.Id = cr.CombinableOrder_Id）= 0）

SQL删除没有子记录的父记录

2 个答案: