SQLserver自定义函数实例:create function dbo.t_bh (@str varchar(20)) returns varchar(20) as begin declare @bh varchar(20),@length int,@i int set @length=12-LEN(@str) if LEN(@str)12 begin set @i=0 while @i@length begin set @str='0'+@str set @i=@i+1 end return @str