如何從MySQL的每個組中選擇第二行

Question

如何從MySQL的每個組中選擇第二行，如下圖所示。

Answer 1

使用以下查詢在MySQL：

SELECT C.groupname，C.marks FROM querysecondval下放置JOIN（SELECT A.groupid，IFNULL（B.groupid，0）groupid2 FROM querysecondval A LEFT JOIN（SELECT B.groupid FROM querysecondval B GROUP BY B.groupname order by B.groupid）B ON A.groupid = B.groupid ）D ON C.groupid = D.groupid WHERE D.groupid2 = 0 GROUP BY C.groupname order by C.groupid