mysql - 多表连接

Question

我有下表:

1. 委员会[ID、名称、Total_Amount、Total_Members、Starting_Date、Ending_Date]

2. committee_group [ID、名称、Total_Members]

3. Group_Member [Id、Group_Id、Member_Name、贡献]

我想从committee_group中选择Name，其中Group_Member的贡献总和等于委员会的Total_Amount

这就是我目前所拥有的

SELECT committee_group.*, Sum(Case When group_member.Group_Id='1'
                                   THEN group_member.Contribution
                                   ELSE 0 END) 
FROM committee_group
  LEFT JOIN group_member ON group_member.Id = committee_group.Id
  LEFT join comitees ON group_member.Contribution = comitees.Total_Amount

Answer 1

这应该有效，

SELECT a.id,a.Name,a.Total_Members,c.Total_Amount
FROM committee_Group a
INNER JOIN (SELECT Name,sum(Contribution) as 'Sum_Con'
            FROM Group_Member
            GROUP BY Name)b on a.Id=b.Id
INNER JOIN comitees c on c.Total_Amount=b.Sum_Con
                     and b.Name=c.Name