Question

我有一个包含以下列的表：

playlistid 
trackname 
playstatus
likes
dislikes
created

playstatus可以具有以下值：0, 1, 2 and 4。

我现在使用的SQL查询是：

 SELECT * from playlist
 WHERE playlistid=$myplaylistid && playstatus=0
 ORDER BY (likes-dislikes) DESC, created ASC

值得一提的是，在任何时候都只有一行有playstatus = 1，一行有playlistid = 3，但是有多行有playstatus = 0和2.

我想更改上面的查询，以便我从playstatus = 3获取1行，playstatus = 1中的1行，以及单个查询中playstatus = 0的3行。所有这些都必须根据您在上面的查询中看到的相同顺序进行选择。

感谢所有帮助！谢谢你的时间！

Answer 1

试试这个

SELECT * from playlist WHERE playlistid=$myplaylistid && playstatus=3
union 
SELECT * from playlist WHERE playlistid=$myplaylistid && playstatus=1
union 
SELECT * from playlist WHERE playlistid=$myplaylistid && playstatus=0
ORDER BY (likes-dislikes) DESC, created ASC

Answer 2

尝试此查询

SELECT * from playlist WHERE playlistid=$myplaylistid && playstatus=1
ORDER BY (likes-dislikes) DESC, created ASC limit 1
union 
SELECT * from playlist WHERE playlistid=$myplaylistid && playstatus=3 
ORDER BY (likes-dislikes) DESC, created ASC limit 1
union 
SELECT * from playlist WHERE playlistid=$myplaylistid && playstatus=0
ORDER BY (likes-dislikes) DESC, created ASC limit 3

Mysql多子查询限制

2 个答案: