--1、创建一个备份表：
select * into Users_Bak from Users
--2、依据某个表进行更新：
update Users_Bak
　　　 set Users_Bak.Mobile = BasicInfo.Mobile,
Users_Bak.Email = BasicInfo.Email
　　 from BasicInfo where Users_Bak.UserName = BasicInfo.UserName

--3、查询正确性
select Users_Bak.Mobile,BasicInfo.Mobile,Users_Bak.Email,BasicInfo.Email from Users_Bak
left join BasicInfo on Users_Bak.UserName = BasicInfo.UserName
--4、改为测试表改为正式表进行更新。