这个SQL怎么写

Question

year：年 quater：季度 quality：质量
+----+------+--------+---------+
| ID | year | quater | quality |
+----+------+--------+---------+
|  1 | 2001 |      1 |     1.2 |
|  2 | 2001 |      2 |       1 |
|  3 | 2001 |      3 |     1.1 |
|  4 | 2001 |      4 |     1.3 |
|  5 | 2002 |      1 |     0.9 |
|  6 | 2002 |      2 |     1.1 |
|  7 | 2002 |      3 |     1.4 |
|  8 | 2002 |      4 |     1.2 |
+----+------+--------+---------+要求这样显示(按四个季度)
+------+---------+---------+---------+---------+
| year | quater1 | quater2 | quater3 | quater4 |
+------+---------+---------+---------+---------+
| 2001 |     1,2 |       1 |     1.1 |     1.3 |
+------+---------+---------+---------+---------+
| 2002 |     0.9 |     1.1 |     1.4 |     1.2 |
+------+---------+---------+---------+---------+

Answer 1

SELECT YEAR, SUM(DECODE (quater, 1, quality)) AS quater1,
       SUM(DECODE (quater, 2, quality)) AS quater2,
       SUM(DECODE (quater, 3, quality)) AS quater3,
       SUM(DECODE (quater, 4, quality)) AS quater4
  FROM test1
GROUP BY YEAR
简单的一句SQL搞定。

Answer 2

if, case反正就是这类的语句，结构和1楼的一样

Answer 3

兄弟，怎么没在SQL区里发啊，呵呵