Orcal删除重复数据

1、查找表中多余的重复记录，重复记录是根据单个字段（Id）来判断

select * from tablename where Id in (select Id from tablename group byId having count(Id) > 1) [and age > 10]；

2、删除表中多余的重复记录，重复记录是根据单个字段（Id）来判断，只留有rowid最小的记录

DELETE from tablename WHERE (id) IN ( SELECT id FROM tablename GROUP BY id HAVING COUNT(id) > 1) AND ROWID NOT IN (SELECT MIN(ROWID) FROM tablename GROUP BY id HAVING COUNT(*) > 1) [and age > 10];

3、查找表中多余的重复记录（多个字段）

select * from tablename a where (a.Id,a.seq) in(select Id,seq from tablename group by Id,seq having count(*) > 1) [and age > 10]；

4、删除表中多余的重复记录（多个字段），只留有rowid最小的记录

delete from tablename a where (a.Id,a.seq) in (select Id,seq from tablename group by Id,seq having count(*) > 1) and rowid not in (select min(rowid) from tablename group by Id,seq having count(*)>1) [and age > 10];

5、查找表中多余的重复记录（多个字段），不包含rowid最小的记录

select * from tablename a where (a.Id,a.seq) in (select Id,seq from tablename group by Id,seq having count(*) > 1) and rowid not in (select min(rowid) from tablename group by Id,seq having count(*)>1) [and age > 10];