pgsql报错 must appear in the GROUP BY clause or be used in an aggregate function
must appear in the GROUP BY clause or be used in an aggregate function
今天在分组统计的时候pgsql报错 must appear in the GROUP BY clause or be used in an aggregate function
,在mysql里面是可以的,但是pgsql报错,这是pgsql一个常见的聚合问题,在SQL3标准以前,选择显示的字段必须出现在在 GROUP BY
中。下面我把问题描述一下:
数据是这样的
我想sum(avg)根据cname 进行计算期望结果为
具体pgsql如下:
SELECT
T .cname,
M .wmname,
T . MAX
FROM
(
SELECT
cname,
MAX (AVG) AS MAX
FROM
makerar
GROUP BY
cname
) T
LEFT JOIN makerar M ON T .cname = M .cname ;
参考:https://www.cnblogs.com/zxhyJack/p/9934259.html
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