Quote: 为了将rank,dense_rank,row_number函数的差别显示出来,我们对已有的基础数据做一些修改,将5763的数据改成与5761的数据相同. 1 update t t1 set local_fare = ( 2 select local_fare from t t2 3 where t1.bill_month = t2.bill_month 4 and t1.net_type = t2.net_type 5 and t2.area_code = ''''5761'''' 6* ) where area_code = ''''5763'''' 07:19:18 SQL> /
8 rows updated.
Elapsed: 00:00:00.01
我们先使用rank函数来计算各个地区的话费排名. 07:34:19 SQL> select area_code,sum(local_fare) local_fare, 07:35:25 2 rank() over (order by sum(local_fare) desc) fare_rank 07:35:44 3 from t 07:35:45 4 group by area_codee 07:35:50 5 07:35:52 SQL> select area_code,sum(local_fare) local_fare, 07:36:02 2 rank() over (order by sum(local_fare) desc) fare_rank 07:36:20 3 from t 07:36:21 4 group by area_code 07:36:25 5 /
07:36:26 SQL> select area_code,sum(local_fare) local_fare, 07:39:16 2 dense_rank() over (order by sum(local_fare) desc ) fare_rank 07:39:39 3 from t 07:39:42 4 group by area_code 07:39:46 5 /
1 select area_code,sum(local_fare) local_fare, 2 row_number() over (order by sum(local_fare) desc ) fare_rank 3 from t 4* group by area_code 07:44:50 SQL> /
a. 取出数据库中最后入网的n个用户 select user_id,tele_num,user_name,user_status,create_date from ( select user_id,tele_num,user_name,user_status,create_date, rank() over (order by create_date desc) add_rank from user_info ) where add_rank <= :n;
b.根据object_name删除数据库中的重复记录 create table t as select obj#,name from sys.obj$; 再insert into t1 select * from t1 数次. delete from t1 where rowid in ( select row_id from ( select rowid row_id,row_number() over (partition by obj# order by rowid ) rn ) where rn <> 1 );
c. 取出各地区的话费收入在各个月份排名. SQL> select bill_month,area_code,sum(local_fare) local_fare, 2 rank() over (partition by bill_month order by sum(local_fare) desc) area_rank 3 from t 4 group by bill_month,area_code 5 /
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