mysql - #1111 - 在 mysql 中无效使用组函数

Question

我有一个包含字段的表 M_DAILY

PS_DATE date,
tp int,
ep int,
mp int,

并且有一个用户定义的函数 nvl(x,y) 的工作版本，如果 x 不为 null 则返回 x，如果 x 为 null 则返回 y

我的 MySQL 查询是-

select sum(avg(case date_format(PS_DATE,'%Y') when '2005' then nvl(tp,0) else 0 end))tp, sum(avg(case date_format(PS_DATE,'%Y') when '2005' then nvl(ep,0) else 0 end)) ep, sum(avg(case date_format(PS_DATE,'%Y') when '2005' then nvl(mp,0) else 0 end)) mp
from M_DAILY
where PS_DATE >= date ('2005-01-01') and PS_DATE <= date ('2005-12-31')
group by PS_DATE;

出现以下错误

#1111 - Invalid use of group function in mysql

请帮忙。

Answer 1

SUM(), COUNT(), AVG(), MIN(), MAX(), etc. are aggregate functions that requires you to specify a GROUP BY, unless you're using them on every column in your SELECT-list.

删除Group By 子句

试试这个

SELECT SUM(tp),SUM(ep),SUM(mp) FROM
(
    SELECT Avg(case date_format(PS_DATE,'%Y') when '2005' then nvl(tp,0) else 0 end) tp,   
           Avg(case date_format(PS_DATE,'%Y') when '2005' then nvl(ep,0) else 0 end) ep, 
           Avg(case date_format(PS_DATE,'%Y') when '2005' then nvl(mp,0) else 0 end) mp   
    FROM M_DAILY 
    WHERE PS_DATE >= date ('2005-01-01') and PS_DATE <= date ('2005-12-31');
) As T