SQL问题(100分)

有一张表,表结构例如:Bh,ParnetID,A,B,C,D;Bh是主键,Parent,A,B三个条件可以决定一条记录.现在问题如下:<br>&nbsp; BH &nbsp; ParentID &nbsp; &nbsp; A &nbsp; &nbsp; B &nbsp; &nbsp; <br>&nbsp; &nbsp;1 &nbsp; &nbsp; &nbsp;1 &nbsp; &nbsp; &nbsp; &nbsp;"aa" &nbsp;"bb" &nbsp; <br>&nbsp; &nbsp;2 &nbsp; &nbsp; &nbsp;1 &nbsp; &nbsp; &nbsp; &nbsp;"aa" &nbsp;"cc"<br>&nbsp; &nbsp;3 &nbsp; &nbsp; &nbsp;2 &nbsp; &nbsp; &nbsp; &nbsp;"aa" &nbsp;"bb"<br>&nbsp; &nbsp;4 &nbsp; &nbsp; &nbsp;2 &nbsp; &nbsp; &nbsp; &nbsp;"aa" &nbsp;"cc"<br><br>如何写出效率较高的SQL语句得出结果为<br><br>&nbsp; BH &nbsp; ParentID &nbsp; &nbsp; A &nbsp; &nbsp; B &nbsp; &nbsp; <br>&nbsp; &nbsp;1 &nbsp; &nbsp; &nbsp;1 &nbsp; &nbsp; &nbsp; &nbsp;"aa" &nbsp;"bb" &nbsp; <br>&nbsp; &nbsp;3 &nbsp; &nbsp; &nbsp;2 &nbsp; &nbsp; &nbsp; &nbsp;"aa" &nbsp;"bb"<br>&nbsp; &nbsp;2 &nbsp; &nbsp; &nbsp;1 &nbsp; &nbsp; &nbsp; &nbsp;"aa" &nbsp;"cc"<br>&nbsp; &nbsp;4 &nbsp; &nbsp; &nbsp;2 &nbsp; &nbsp; &nbsp; &nbsp;"aa" &nbsp;"cc"

select * from table_name order by a,b

这是干啥呢

不行的,这种排序的位置可能会混乱了,两条相同的时候BH小的一定要排前面了.

应该是ParentID小的排在前面.

你是问问题还是脑筋急转弯啊？问题都没说明白啥意思。

select * from table_name order by a,b,ParentID

已经解决了，谢谢各位。