Question

我编写了一个触发器，当MTRL表中的PRICER01列更新时，该触发器必须更新CCCMPMTRL表。表MTRL中的主键也是一个名为MTRL的列，我也保留在必须更新（CCCMPMTRL）作为外键的表中。问题是每当我更新MTRL表时，在CCCMPMTRL中，值都会更新我在MTRL中的所有记录，但我只想要一个，当前的一个。我做错了什么？

代码如下所示：

CREATE TRIGGER dbo.[test_Price]
ON dbo.[MTRL]
AFTER UPDATE
AS
    DECLARE @MTRL INT;
    DECLARE @OLDPRICER01 FLOAT(2);
    DECLARE @NEWPRICER01 FLOAT(2);
    DECLARE @MPMTRL INT;
    SET @MTRL = (SELECT I.MTRL FROM INSERTED I,MTRL M WHERE M.MTRL = I.MTRL);
    SET @MPMTRL = (SELECT MTRL FROM MTRL WHERE MTRL=@MTRL);
    SET @OLDPRICER01 = (SELECT PRICER01 FROM MTRL WHERE MTRL =@MTRL AND SODTYPE = 51)
    SET @NEWPRICER01 = (SELECT PRICER01 FROM INSERTED WHERE MTRL = @MTRL AND SODTYPE = 51)
    IF(NOT EXISTS(SELECT CM.MTRL FROM CCCMPMTRL CM, INSERTED I WHERE CM.MTRL = I.MTRL))
        INSERT INTO CCCMPMTRL
            SELECT M.MTRL,D.PRICER01,I.PRICER01 FROM INSERTED I, DELETED D, MTRL M WHERE I.MTRL = @MTRL
    ELSE
        IF(@OLDPRICER01 <> @NEWPRICER01)
            UPDATE CCCMPMTRL 
            SET OLDPRICER01 = @OLDPRICER01,
                NEWPRICER01 = @NEWPRICER01
                    FROM CCCMPMTRL AS CM 
                    WHERE CM.MTRL = @MTRL

Answer 1

试试这个

UPDATE CM
    SET OLDPRICER01 = D.PRICER01,
        NEWPRICER01 = I.PRICER01
    FROM INSERTED I
        JOIN DELETED D ON D.MTRL=I.MTRL
        JOIN CCCMPMTRL CM ON CM.MTRL=I.MTRL
    WHERE D.PRICER01 <> I.PRICER01

INSERT INTO CCCMPMTRL
    SELECT I.MTRL, D.PRICER01, I.PRICER01 
    FROM INSERTED I
        JOIN DELETED D ON D.MTRL=I.MTRL
        LEFT JOIN CCCMPMTRL C ON C.MTRL=I.MTRL
    WHERE C.MTRL IS NULL

因为UPDATE语句在CCMPMTRL上使用内连接，所以它只会更新已存在行的位置，而INSERT语句使用左外连接来排除MTRL的现有值。

无论是一次插入一行还是多行，这都应该有效，并且不需要所有这些局部变量。

触发器更新表中的所有值

1 个答案: