我需要编写一个AFTER UPDATE触发器。当employees表的工资率被修改时。它需要获取该信息并在ChangeLog表中创建一行。我的表格如下:
员工人数:
EmployeeID INT (PK),
PayPerHour MONEY
变更日志:
ChangeID INT (PK),
EmpID (FK to EmployeeID),
ChangedBy NVARCHAR(30),
DateChanged SMALLDATETIME,
OldRate MONEY,
NewRate MONEY
这是我整理的。没有错误,但是没有在ChangeLog中创建行。(我的印象是插入=新数据,已删除=旧数据)。理想情况下,EmpID将匹配,ChangedBy将是System用户,DateChanged将是时间戳,OldRate将是更新前的速率,NewRate将是更新后的速率。
CREATE TRIGGER PayRate_UPDATE
ON Employees
AFTER UPDATE
AS
BEGIN
DECLARE @EmpID INT
SELECT @EmpID = EmployeeID
FROM inserted
DECLARE @OldRate MONEY
SELECT @OldRate = PayPerHour
FROM deleted
DECLARE @DateChanged SMALLDATETIME
SELECT @DateChanged = GETDATE()
DECLARE @ChangedBy NVARCHAR(128)
SELECT @ChangedBy = suser_sname()
DECLARE @NewRate MONEY
SELECT @NewRate = PayPerHour
FROM inserted
IF UPDATE(PayPerHour)
UPDATE ChangeLog
SET EmpID = @EmpID,
ChangedBy = @ChangedBy,
DateChanged = @DateChanged,
OldRate = @OldRate,
NewRate = @NewRate
END;
您的代码中有几个问题:
您的代码应类似于:
CREATE TRIGGER PayRate_UPDATE ON Employees
AFTER UPDATE
AS
BEGIN
DECLARE @DateChanged SMALLDATETIME
SELECT @DateChanged = GETDATE()
DECLARE @ChangedBy NVARCHAR(128)
SELECT @ChangedBy = SUSER_SNAME()
IF UPDATE(PayPerHour)
INSERT [ChangeLog]
(
EmpID,
ChangedBy,
DateChanged,
OldRate,
NewRate
)
SELECT
i.EmployeeID,
@ChangedBy,
@DateChanged,
d.PayPerHour,
i.PayPerHour
FROM
INSERTED i
LEFT JOIN DELETED d
ON i.EmployeeID = d.EmployeeID
END;
因此,修订后的触发器现在可以处理每个人都获得加薪的情况,例如
UPDATE Employees SET PayPerHour = PayPerHour * 1.1 -- everyone gets a 10% payrise YAY!
而且您的变更日志的确保留了每个员工薪资水平每次更新的历史记录。
本文收集自互联网,转载请注明来源。
如有侵权,请联系[email protected] 删除。
我来说两句