摘要： 1.查询表内重复的字段select id from table1 where id in(select id from table1 group by id having count(id)>1)2.select查询添加自增长的列 作为标识列例子：Select (Select sum(1) from Table1 where ID 1过滤重复数据SELECT * FROM tablename GROUP BY colname HAVING COUNT(*) = 1http://blog.csdn.net/zhoujiaoshou/article/details/7928351====== 阅读全文