MySQL Order By日期列和整数列，但是指定整数列的排序规则？可能吗？
您可以借助ORDERBYCASE语句来实现。语法如下-
SELECT *FROM yourTableName ORDER BY CASE yourIntegerColumnName1 WHEN 2 THEN 1 ELSE 0 END DESC ,yourDateColumnName ASC;
为了理解上述语法，让我们创建一个表。创建表的查询如下-
mysql> create table OrderByCaseDemo -> ( -> Id int NOT NULL AUTO_INCREMENT, -> GroupId int, -> ArrivalDate date, -> PRIMARY KEY(Id) -> );
使用insert命令在表中插入一些记录。查询如下-
mysql> insert into OrderByCaseDemo(GroupId,ArrivalDate) values(2,'19/02/06'); mysql> insert into OrderByCaseDemo(GroupId,ArrivalDate) values(1,'20/02/06'); mysql> insert into OrderByCaseDemo(GroupId,ArrivalDate) values(3,'18/02/06'); mysql> insert into OrderByCaseDemo(GroupId,ArrivalDate) values(3,'21/02/06'); mysql> insert into OrderByCaseDemo(GroupId,ArrivalDate) values(2,'17/02/06'); mysql> insert into OrderByCaseDemo(GroupId,ArrivalDate) values(1,'22/02/06');
使用select语句显示表中的所有记录。查询如下-
mysql> select *from OrderByCaseDemo;
以下是输出-
+----+---------+-------------+ | Id | GroupId | ArrivalDate | +----+---------+-------------+ | 1 | 2 | 2019-02-06 | | 2 | 1 | 2020-02-06 | | 3 | 3 | 2018-02-06 | | 4 | 3 | 2021-02-06 | | 5 | 2 | 2017-02-06 | | 6 | 1 | 2022-02-06 | +----+---------+-------------+ 6 rows in set (0.00 sec)
这是按日期排序的查询列以及整数列-
mysql> select *from OrderByCaseDemo order by case GroupId when 2 then 1 else 0 end desc,ArrivalDate asc;
以下是输出-
+----+---------+-------------+ | Id | GroupId | ArrivalDate | +----+---------+-------------+ | 5 | 2 | 2017-02-06 | | 1 | 2 | 2019-02-06 | | 3 | 3 | 2018-02-06 | | 2 | 1 | 2020-02-06 | | 4 | 3 | 2021-02-06 | | 6 | 1 | 2022-02-06 | +----+---------+-------------+ 6 rows in set (0.00 sec)