select IDENTITY( int ,1,1) as SortID from tb_order 仅当 SELECT 语句中有 INTO 子句时,才能使用 IDENTITY 函数。 select IDENTITY( int ,1,1) as SortID,* into # Temp from tb_order 无法使用 SELECT INTO 语句将标识列添加到表 '#Temp' ,该表的列 'ID' 已继承了标识属性。 这样写才是正确的, select 后面不能包含*,不能包含ID号,必须写字段名 select IDENTITY( int ,1,1) as SortID,OrderNumber into # Temp from tb_order select * from # Temp 多表获取ID号 select IDENTITY( int ,1,1) as SortID,OrderNumber,a.ID as ID into # Temp from tb_order as a left join tb_OrderList as b on a.ID=b.OrderID 单表获取ID号,直接写ID会报错的 select IDENTITY( int ,1,1) as SortID,OrderNumber,a.ID*1 as ID into # Temp from tb_order as a ROW_NUMBER() 这样写可以代替 select ROW_NUMBER()over( order by id) as SortID from tb_order 同样获取SortID IDENTITY( int ,1,1) 查询速度会快很多 |
SQL IDENTITY(int,1,1) 用法
发布时间 2023-04-11 09:08:05作者: GU天乐乐乐!