触发器

ALTER TRIGGER [dbo].[同步更新类别] 
   ON  [dbo].[计划] 
   FOR  UPDATE
AS 
    declare @bm_i nvarchar(128)
    declare @bm_d nvarchar(128)
    declare @n_i int
    declare @n_d int
    declare @wenhao_i nvarchar(128)
    declare @wenhao_d nvarchar(128)
    declare @lb_i nvarchar(128)
    declare @lb_d nvarchar(128)
    select @bm_i=编码,@n_i=年,@wenhao_i=文号,@lb_i=类别 from inserted
    select @bm_d=编码,@n_d=年,@wenhao_d=文号,@lb_d=类别 from deleted
    if(@bm_i<>@bm_d) and (@n_i<>@n_d) and (@wenhao_i<>@wenhao_d) and (@lb_i<>@lb_d) 
    BEGIN
        update 计划项目 set 类别=@lb_i
        where 编码=@bm_i and 年=@n_i and 文号=@wenhao_i and 类别=@lb_i
    END

if(@bm_i<>@bm_d) and (@n_i<>@n_d) and (@wenhao_i<>@wenhao_d) and (@lb_i<>@lb_d) 

--改成
if (@lb_i <> @lb_d)

 if(@bm_i=@bm_d) and (@n_i=@n_d) and (@wenhao_i=@wenhao_d) and (@lb_i<>@lb_d) 

--看LZ的说明，应该是这个意思吧???

    if(@bm_i<>@bm_d) and (@n_i<>@n_d) and (@wenhao_i<>@wenhao_d) and (@lb_i<>@lb_d) 
    BEGIN
        print 123 --测试一下是否进入了if语句
        update 计划项目 set 类别=@lb_i
        where 编码=@bm_i and 年=@n_i and 文号=@wenhao_i and 类别=@lb_i
    END