如果初始行是随机的,其余的按MySQL的标准排序,该如何选择行呢?
为此,您可以使用ORDERBYCASE语句。让我们创建一个表-
mysql> create table DemoTable1926 ( Position varchar(20), Number int );
使用插入命令在表中插入一些记录-
mysql> insert into DemoTable1926 values('Highest',50); mysql> insert into DemoTable1926 values('Highest',30); mysql> insert into DemoTable1926 values('Lowest',100); mysql> insert into DemoTable1926 values('Lowest',120); mysql> insert into DemoTable1926 values('Lowest',90);
使用select语句显示表中的所有记录-
mysql> select * from DemoTable1926;
这将产生以下输出-
+----------+--------+ | Position | Number | +----------+--------+ | Highest | 50 | | Highest | 30 | | Lowest | 100 | | Lowest | 120 | | Lowest | 90 | +----------+--------+ 5 rows in set (0.00 sec)
如果初始行是随机的并且按条件按其余顺序排序,这是选择行的查询-
mysql> select * from DemoTable1926 order by Position desc,case Position when 'Highest' then rand() else Number end asc;
这将产生以下输出-
+----------+--------+ | Position | Number | +----------+--------+ | Lowest | 90 | | Lowest | 100 | | Lowest | 120 | | Highest | 50 | | Highest | 30 | +----------+--------+ 5 rows in set (0.00 sec)