问题描述
这就是你想要的:
select x.name
, count(*) as cntNames
, sum(x.cntDetails) as cntDetails
from (
SELECT i.name, COUNT(*) as cntDetails
FROM item AS i
INNER JOIN item_category AS ic ON i.i_category_id = ic.ic_id
INNER JOIN idetail AS id ON ic.ic_id = id.id_category_id
WHERE ic.ic_id = 1002
-- NOTICE THE 2nd Value in the group by!
GROUP BY i.name,id.id_category_id
) x
group by name
解决方法
我有3张桌子。我想按item.name分组并计算可以在idetail中找到的次数。此查询仅计算所有行,不按行分组。
有人知道如何解决吗?
SELECT i.name,COUNT(i.name)
FROM item AS i
INNER JOIN item_category AS ic ON i.i_category_id = ic.ic_id
INNER JOIN idetail AS id ON ic.ic_id = id.id_category_id
WHERE ic.ic_id = 1002
GROUP BY i.name