摘要：1.删除重复项, 只保留第一条deletetable t1where t1.ID not in ( select min(t2.ID) fromtable t2 group by t2.ColName)2.查找重复记录select t1.ID, count(*) from table group by t1.ID having count(*) > 1 order by count(*) d... 阅读全文