Question

我需要一个帮助构建一个mysql数据库的sql查询。 2表如下：

tblcities (id,name)
tblmembers(id,name,city_id)

现在我想要检索具有最多“成员”数量的“城市”详细信息。

此致

Answer 1

SELECT tblcities.id, tblcities.name, COUNT(tblmembers.id) AS member_count
FROM tblcities
LEFT JOIN tblmembers ON tblcities.id = tblmembers.city_id
GROUP BY tblcities.id
ORDER BY member_count DESC
LIMIT 1

基本上：检索所有城市并计算每个城市有多少成员，按降序排列该成员数，先计算最高数量 - 然后只显示第一个城市。

Answer 2

可怕，但这是一种做法：

SELECT * FROM tblcities WHERE id IN (
    SELECT city_id
    FROM tblMembers
    GROUP BY city_id
    HAVING COUNT(*) = (
        SELECT MAX(TOTAL)
        FROM (
            SELECT COUNT(*) AS TOTAL
            FROM tblMembers
            GROUP BY city_id
        ) AS AUX
    )
)

这样，如果有平局，你仍然可以获得所有会员人数最多的城市......

Answer 3

Select ...
From tblCities As C
    Join    (
            Select city_id, Count(*) As MemberCount
            From tblMembers
            Order By Count(*) Desc
            Limit 1
            ) As MostMembers
        On MostMembers.city_id = C.id

Answer 4

select top 1 c.id, c.name, count(*)   
from tblcities c, tblmembers m 
where c.id = m.city_id 
group by c.id, c.name 
order by count(*) desc

帮助SQL QUERY OF JOIN + COUNT + MAX

4 个答案: