一.定义表变量 代码如下: DECLARE T1 table ( UserID int , UserName nvarchar(50), CityName nvarchar(50) ); insert into T1 (UserID,UserName,CityName) values (1,’a’,’上海’) insert into T1 (UserID,UserName,CityName) values (2,’b’,’北京’) insert into T1 (UserID,UserNam