--------
table_1 |
--------
type_id    type       
-----------------
1          a          
2          b          
2          c  --------
table_2 |
--------
id         type_id    year
--------------------------
1          1          2009
2          1          2008
3          1          2001
---------------------------
4          2          2008
5          2          2005
--------------------------
6          3          2009
7          3          2010
8          3          2000
-------------------------------------以上两个关联表,现在能得到这三个type_id,我想弄出下面这种结果:type_id       type               year
---------------------------------------
1             a               2001—2009
2             b               2005—2008
3             c               2009—2010
--------------------------------------------
这个循环该怎么写啊,我知道是嵌套的,但是写了整整半天都没弄出来,嵌套循环,还加个求最值,后者倒是好做
球大侠给个思路,不胜感谢