mysql - 在 View 内分组

Question

这是我正在努力解决的问题...我有三个这样的表:

Practice
* PracticeID
* PracticeName

Group
* GroupID
* Sales
* Salaries
* Overheads

Values
* PracticeID
* GroupID
* Income
* Expense

我想要做的是准备一个 View ，通过“组”表中的组名称来总结“值”中的收入和支出。我可以得到一行一行的摘要，但我遇到了如何在我当前拥有的代码中包含组子句的问题，如下所示:

SELECT Practice.PracticeName, Group.Groupname, Values.Income, Values.Expenses    
FROM     values INNER JOIN
                  Practice ON values.PracticeID = Practice.PracticeID INNER JOIN
                  Group ON Values.NominalGroupID = Group.GroupID

Answer 1

试试这个:

SELECT Practice.PracticeName, Group.Groupname, SUM(Values.Income) as SumIncome, SUM(Values.Expenses ) as SumExpences   
FROM     values INNER JOIN
                  Practice ON values.PracticeID = Practice.PracticeID INNER JOIN
                  Group ON Values.NominalGroupID = Group.GroupID
Group By Group.Groupname