如何在有些复杂的mysql查询中按顺序分组

Question

(SELECT dtable.*, new_apps.top as t1 FROM app_detailsvvv as dtable INNER JOIN new_apps ON
new_apps.trackId=dtable.trackId WHERE (SELECT COUNT(*) AS c FROM compositions as dtablev
WHERE parent='169469' AND trackId=dtable.trackId AND new_apps.top > 0)>0) UNION
(SELECT *, 301 FROM app_detailsvvv as dtable WHERE (SELECT COUNT(*) AS c FROM compositions   
as dtablev WHERE parent='169469' AND trackId=dtable.trackId)>0) ORDER BY t1 ASC, trackName 
ASC LIMIT 0,12

这个查询给我带来了重复，我如何按 trackId 分组？

Answer 1

将 trackid 作为 SELECT 语句的一部分 ...

SELECT new_apps.trackId,
       ..etc...
..
..

GROUP BY 1

确保您的其余 SELECT 项（包括子 SQL 查询）已聚合 - 例如 MAX、FIRST、SUM 或将它们分组为单个结果的内容。