distinct多列去重的及檢查重複資料語句
--去重查詢方法一:根據id
select * from sxe where id in(select min(id) from sxe group by username) order by id asc;
--去重查詢方法二:根據rownum
select * from (select s.*,rownum rn from sxe s ) x where x.rn in (select min(rownum) from sxe group by username) order by id asc;
--去重查詢方法三:根據rowid
select * from (select s.*,rowid rid from sxe s) x where x.rid in (select min(rowid) from sxe group by username) order by id asc;
select s.*,rowid from sxe s where rowid in (select min(rowid) from sxe group by username) order by id asc;
--檢查重複的列及條數
select col001,sum(1) as ufo from lhsjb group by col001 having sum(1) > 1