tweety：
haitao给出了正解,还是我笨,本来按李银同学的思路,我应该能够举一反三的
[阅读: 514] 2004-11-11 09:50:01
SELECT Tb.*
FROM (SELECT a, c cc, MAX(d) dd
FROM (SELECT tb.*
FROM (SELECT a, MAX(c) cc
FROM tb
GROUP BY a) tba LEFT JOIN
tb ON tb.a = tba.a AND tb.c = tba.cc) tba
GROUP BY a, c) tba LEFT OUTER JOIN
Tb ON Tb.A = tba.a AND Tb.C = tba.cc AND Tb.D = tba.dd
只是我不明白为什么要用left outter join,我用inner join也是一样的啊??
......... @@@@@ @@@@@.........
........ @ @ @ @.........
....... @@@ @ @ .........
...... @@ @ @ .........
...... @@@@@@@ @@@@@ th .......
.... ----------------------- ......
... C E N T U R Y ....
... ----------------------- ...
.. @@@@@ @@@@@ @ @ @@@@@ ..
== @ @ @ @ @ ==
__||__ @ @@@@ @ @ __||__
| | @ @ @ @ @ | |
_________|______|_____ @ @@@@@ @ @ @ _____|______|____
| -ICP -IDC -ISP |