Question

是否有一些有效的方法来编写在公共表上连接GROUP BY的各种结果的查询？ MySQL如何处理将subGROUP上的aggreagate函数的结果与原始表中的完整字段合并？

我正在使用它并且它很慢（我还需要除CONDITION = 1之外的其他条件）

SELECT a.CID,a.AS_ALL,b.AS_ACTIVE FROM 
            (SELECT CID,COUNT(DISTINCT RAID) AS AS_ALL FROM MYTABLE GROUP BY CID) a
            LEFT JOIN
            (SELECT CID,COUNT(DISTINCT RAID) AS AS_ACTIVE FROM MYTABLE WHERE CONDITION=1 GROUP BY CID ) b ON a.CID=b.CID;

也可以使用像？ MySQL总是会正确地将COLUMN_A与聚合结果合并吗？

SELECT  COLUMN_A COUNT(DISTINCT COLUMN_A), SUM(COLUMN_A),SUM(COLUMN_B) FROM ATABLE WHERE CONDITION=1 GROUP BY COLUMN_C

感谢您的建议

Answer 1

试试这个：

SELECT CID,COUNT(DISTINCT RAID) AS AS_ALL,SUM(IF(CONDITION=1, 1, 0)) AS AS_ACTIVE 
FROM MYTABLE GROUP BY CID

MySQL有效且正确地链接GROUP BY结果

1 个答案: