如何找到重复的行？

Question

我有75000行记录,我需要知道有多少重复,我怎么能在MySQL Query中做到这一点？

Answer 1

此查询将返回所有重复的行以及它们重复的次数

SELECT Col1, Col2,..ColLast, Count(*) As NumDups FROM YourTable
GROUP BY Col1,Col2,...,ColLast
HAVING COUNT(*) > 1;