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: 620] 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??
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