Question

我有两张桌子：

tblEmployee

EmployeeID (PK), Name, Age, Department

tblDesignation

EmployeeID(FK), Designation, DesignationID

只有在指定表中没有记录时，我才需要帮助编写一个存储过程来删除员工记录。（仅在未指定指定时删除employeeID）

我不确定是否应该使用ON DELETE RESTRICT约束或NOT EXISTS子句。

Answer 1

那么你可以为你的目的拥有以下代码。请原谅语法

create procedure usp_deleteemployee
as 
begin
    delete from tblEmployee 
    where id not in (select empid from tblDesignation);
end

或者你也可以尝试存在。不确定语法

DELETE tblEmployee 
FROM tblEmployee 
WHERE NOT EXISTS (SELECT 1 
                  FROM tblDesignation 
                  WHERE tblEmployee.Id = tblDesignation.empid)

Answer 2

您可以尝试下面的内容。

DELETE
E
FROM
tblEmployee E
LEFT JOIN tblDesignation D
ON E.EmployeeID = D.EmployeeID
WHERE
D.EmployeeID IS NULL

希望这有助于!!

SQL：当子元素不存在时删除父元素

2 个答案: