Question

Table A

• tableAID
• tableBID
• grade

Table B

• tableBID
• name
• description

Table A links to Table b from the tableBID found in both tables.

If I want to find the row in Table A, which has the highest grade, for each row in Table B, I would write my query like this:

select max(grade) from TableA group by tableBID

However, I don’t just want the grade, I want the grade plus id of that row.

Answer 1

You could try something like

SELECT  a.*
FROM    TableA a INNER JOIN
        (
            SELECT  tableBID,
                    MAX(grade) MaxGrade
            FROM    TableA
            GROUP BY tableBID
        ) B ON a.tableBID = B.tableBID AND a.grade = B.MaxGrade

Using the Sql Server 2005 ROW_NUMBER function you could also try

SELECT  tableAID,
        tableBID,
        grade
FROM    (
            SELECT  *,
                    ROW_NUMBER() OVER (PARTITION BY tableBID ORDER BY grade DESC) RowNum
            FROM    @TableA
        ) A
WHERE   a.RowNum = 1