首先以升序查询行的非空值，然后显示NULL值
为此，请使用ORDERBYISNULL()。让我们首先创建一个表-
create table DemoTable669 ( StudentId int NOT NULL AUTO_INCREMENT PRIMARY KEY, StudentScore int );
使用插入命令在表中插入一些记录-
insert into DemoTable669(StudentScore) values(45) ; insert into DemoTable669(StudentScore) values(null); insert into DemoTable669(StudentScore) values(89); insert into DemoTable669(StudentScore) values(null);
使用select语句显示表中的所有记录-
select *from DemoTable669;
这将产生以下输出-
+-----------+--------------+ | StudentId | StudentScore | +-----------+--------------+ | 1 | 45 | | 2 | NULL | | 3 | 89 | | 4 | NULL | +-----------+--------------+ 4 rows in set (0.00 sec)
以下是查询以升序显示非空值。空值将随后显示-
select *from DemoTable669 ORDER BY ISNULL(StudentScore),StudentScore;
这将产生以下输出-
+-----------+--------------+ | StudentId | StudentScore | +-----------+--------------+ | 1 | 45 | | 3 | 89 | | 2 | NULL | | 4 | NULL | +-----------+--------------+ 4 rows in set (0.00 sec)