剔除重复次数最多的记录

删除重复次数最多的记录
表tb中有3个字段，其中有很多重复记录，现在想把重复次数最多的记录删除，可用下面的命令把所有的记录都删除了,请大虾们帮帮忙,谢谢。

DELETE FROM tb WHERE EXISTS(SELECT MAX(fc) FROM (SELECT ax,ay,az,COUNT(*) fc FROM tb GROUP BY ax,ay,az) a)


[解决办法]

SQL code

delete afrom tb ainner join(select top 1 ax,ay,az from tb group by ax,ay,az order by count(1) desc) b on a.ax=b.ax and a.ay=b.ay and a.az=b.az