mysql - 限制 mysql 结果

Question

我正在尝试编写一个 SQL 语句来返回一个人每个主题的最新记录，

Database
Counter,Name,Subject,Grade
1,PersonA,Maths,C
2,PersonB,Maths,B
3,PersonA,English,B
4,PersonB,English,A
5,PersonA,Maths,A
6,PersonB,Maths,B

我想返回 PersonA 的最新结果

5,PersonA,Maths,A
3,PersonA,English,B

这将如何实现？

Answer 1

Select t1.Name,t1.Subject,t1.Grade
From SomeTableName t1
inner join (Select Name,Subject,Max(Counter) As Counter 
            From SomeTable 
            Group By Name,Subject) t2
On t1.counter = t2.counter