关于SQL触发器，请大侠快进来帮忙！

[ericliang101]

以下是我的SQL触发器，现在想在当中插入一个条件，当UDF07是空白时，不更新MC003。请问怎么样写呢？？？急！！！请大侠帮忙！

set nocount off
-- ================================================
SET ANSI_NULLS ON

-- ================================================
CREATE TRIGGER [dbo].[PURTH_UPD1] ON [dbo].[PURTH]
FOR UPDATE
AS
set nocount on

DECLARE
@TH004 CHAR(20),
@TH009 CHAR(10),
@UDF07 VARCHAR(255)

IF UPDATE(TH030)
SELECT @TH004=TH004,@TH009=TH009,@UDF07=UDF07
FROM INSERTED

BEGIN
UPDATE INVMC SET INVMC.MC003=@UDF07 WHERE
MC001=@TH004 AND MC002=@TH009
END

[中国风]

CREATE TRIGGER [dbo].[PURTH_UPD1] ON [dbo].[PURTH] 
FOR UPDATE
AS
set nocount on

DECLARE 
@TH004 CHAR(20),
@TH009 CHAR(10),
@UDF07 VARCHAR(255)

IF UPDATE(TH030)
SELECT @TH004=TH004,@TH009=TH009,@UDF07=UDF07 
FROM INSERTED

IF @UDF07>''
BEGIN
UPDATE  INVMC
SET     INVMC.MC003 = @UDF07
WHERE   MC001 = @TH004
        AND MC002 = @TH009
END

IF @UDF07>''--加上，空字符（‘’）和空值（NULL）时都不更新 只判断空值时 IF @UDF07 IS NOT NULL

[ericliang101]

非常感谢大侠的帮忙。处理好了，谢谢！