我想从我的sql表中计算每日平均销售额。我尝试使用以下查询,但它给出错误,说"关键字选择附近的语法不正确">
select avg(select sum(total) from canteen group by date) as average from canteen
不要嵌套聚合函数。 这是您希望获得每个日期的总和:
select day, sum(total)
from canteen
group by day;
您可以使用子查询获取平均值:
select avg(total)
from (select day, sum(total) as total
from canteen
group by day
) c;
或者,一个更简单的替代方案:
select sum(total) / count(distinct day)
from canteen;
最好尝试
使用这样的子查询:
select avg(total) from(select sum(total) from canteen group by date)
如果您不为嵌套查询而烦恼,我更喜欢;
select avg(total) from(select sum(total) as total from canteen group by date) as T
正确的语法是
SELECT date, avg(total) average FROM (
SELECT date, sum(total)total FROM canteen GROUP BY DATE
)AS A
grouP BY date