SQL 获取字符串中大写字母或小写字母

if exists(select * from sys.objects where name='GetUpper') drop function dbo.GetUpper go CREATE function GetUpper(@words varchar(16)) returns varchar(8000) as begin DECLARE @s VARCHAR(MAX)= @words --待截取字符串 DECLARE @temp VARCHAR(MAX)='' --临时变量 SELECT @temp=@temp+SUBSTRING(ch, sv.number,