oracle 10g+ 行列转换

WITH t AS(  SELECT 1 AS sno, 1 AS cno, 5 AS grade    FROM dual  UNION ALL  SELECT 1, 2, 6    FROM dual  UNION ALL  SELECT 1, 3, 10    FROM dual  UNION ALL  SELECT 2, 3, 10    FROM dual  UNION ALL  SELECT 2, 2, 10    FROM dual  UNION ALL  SELECT 3, 1, 9    FROM dual  UNION ALL  SELECT 3, 2, 9    FROM dual)  SELECT a.sno, Max(a.aa)    FROM (SELECT sno,                 wm_concat(cno || ',' || grade) over(partition BY sno order by cno, grade) AS aa            FROM t) a   GROUP BY a.sno;

 

运行一下就知道是啥意思了