Oracle 分析函数使用介绍
分析函数是oracle816引入的一个全新的概念,为我们分析数据提供了一种简单高效的处理方式.在分析函数出现以前,我们必须使用自联查询,子查询或者内联视图,甚至复杂的存储过程实现的语句,现在只要一条简单的sql语句就可以实现了,而且在执行效率方面也有相当大的提高.下面我将针对分析函数做一些具体的说明.
今天我主要给大家介绍一下以下几个函数的使用方服务器托管网法
1.自动汇总函数rollup,cube,
2.rank 函数, rank,dense_rank,row_number
3. lag,lead函数
4. sum,avg,的移动增加,移动平均数
5. ratio_to_report报表处理函数
6. first,last取基数的分析函数
基础数据
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1. 使用rollup函数的介绍
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1. 使用cube函数的介绍 |
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1 rollup 和 cube函数的再深入
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2. rank函数的介绍 介绍完rollup和cube函数的使用,下面我们来看看rank系列函数的使用方法. 问题2.我想查出这几个月份中各个地区的总话费的排名. |
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2. rank函数的介绍
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
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 /
BILL_MONTH AREA_CODE LOCAL_FARE AREA_RANK
--------------- --------------- -------------- ----------
200405 5765 25057.74 1
200405 5761 13060.43 2
200405 5763 13060.43 2
200405 5762 12643.79 4
200405 5764 12487.79 5
200406 5765 26058.46 1
200406 5761 13318.93 2
200406 5763 13318.93 2
200406 5764 13295.19 4
200406 5762 12795.06 5
200407 5765 26301.88 1
200407 5761 13710.27 2
200407 5763 13710.27 2
200407 5764 13444.09 4
200407 5762 13224.30 5
200408 5765 27130.64 1
200408 5761 14135.78 2
200408 5763 14135.78 2
200408 5764 13929.69 4
200408 5762 13376.47 5
20 rows selected.
SQL>
3. lag和lead函数介绍
取出每个月的上个月和下个月的话费总额
1 select area_code,bill_month, local_fare cur_local_fare,
2 lag(local_fare,2,0) over (partition by area_code order by bill_month ) pre_local_fare,
3 lag(local_fare,1,0) over (partition by area_code order by bill_month ) last_local_fare,
4 lead(local_fare,1,0) over (partition by area_code order by bill_month ) next_local_fare,
5 lead(local_fare,2,0) over (partition by area_code order by bill_month ) post_local_fare
6 from (
7 select area_code,bill_month,sum(local_fare) local_fare
8 from t
9 group by area_code,bill_month
10* )
SQL> /
AREA_CODE BILL_MONTH CUR_LOCAL_FARE PRE_LOCAL_FARE LAST_LOCAL_FARE NEXT_LOCAL_FARE POST_LOCAL_FARE
--------- ---------- -------------- -------------- --------------- --------------- ---------------
5761 200405 13060.433 0 0 13318.93 13710.265
5761 200406 13318.93 0 13060.433 13710.265 14135.781
5761 200407 13710.265 13060.433 13318.93 14135.781 0
5761 200408 14135.781 13318.93 13710.265 0 0
5762 200405 12643.791 0 0 12795.06 13224.297
5762 200406 12795.06 0 12643.791 13224.297 13376.468
5762 200407 13224.297 12643.791 12795.06 13376.468 0
5762 200408 13376.468 12795.06 13224.297 0 0
5763 200405 13060.433 0 0 13318.93 13710.265
5763 200406 13318.93 0 13060.433 13710.265 14135.781
5763 200407 13710.265 13060.433 13318.93 14135.781 0
5763 200408 14135.781 13318.93 13710.265 0 0
5764 200405 12487.791 0 0 13295.187 13444.093
5764 200406 13295.187 0 12487.791 13444.093 13929.694
5764 200407 13444.093 12487.791 13295.187 13929.694 0
5764 200408 13929.694 13295.187 13444.093 0 0
5765 200405 25057.736 0 0 26058.46 26301.881
5765 200406 26058.46 0 25057.736 26301.881 27130.638
5765 200407 26301.881 25057.736 26058.46 27130.638 0
5765 200408 27130.638 26058.46 26301.881 0 0
20 rows selected.
利用lag和lead函数,我们可以在同一行中显示前n行的数据,也可以显示后n行的数据.
4. sum,avg,max,min移动计算数据介绍
计算出各个连续3个月的通话费用的平均数
1 select area_code,bill_month, local_fare,
2 sum(local_fare)
3 over ( partition by area_code
4 order by to_number(bill_month)
5 range between 1 preceding and 1 following ) "3month_sum",
6 avg(local_fare)
7 over ( partition by area_code
8 order by to_number(bill_month)
9 range between 1 preceding and 1 following ) "3month_avg",
10 max(local_fare)
11 over ( partition by area_code
12 order by to_number(bill_month)
13 range between 1 preceding and 1 following ) "3month_max",
14 min(local_fare)
15 over ( partition by area_code
16 order by to_number(bill_month)
17 range between 1 preceding and 1 following ) "3month_min"
18 from (
19 select area_code,bill_month,sum(local_fare) local_fare
20 from t
21 group by area_code,bill_month
22* )
SQL> /
AREA_CODE BILL_MONTH LOCAL_FARE 3month_sum 3month_avg 3month_max 3month_min
--------- ---------- ---------------- ---------- ---------- ---------- ----------
5761 200405 13060.433 26379.363 13189.6815 13318.93 13060.433
5761 200406 13318.930 40089.628 13363.2093 13710.265 13060.433
5761 200407 13710.265 41164.976 13721.6587 14135.781 13318.93
40089.628 = 13060.433 + 13318.930 + 13710.265
13363.2093 = (13060.433 + 13318.930 + 13710.265) / 3
13710.265 = max(13060.433 + 13318.930 + 13710.265)
13060.433 = min(13060.433 + 13318.930 + 13710.265)
5761 200408 14135.781 27846.046 13923.023 14135.781 13710.265
5762 200405 12643.791 25438.851 12719.4255 12795.06 12643.791
5762 200406 12795.060 38663.148 12887.716 13224.297 12643.791
5762 200407 13224.297 39395.825 13131.9417 13376.468 12795.06
5762 200408 13376.468 26600.765 13300.3825 13376.468 13224.297
5763 200405 13060.433 26379.363 13189.6815 13318.93 13060.433
5763 200406 13318.930 40089.628 13363.2093 13710.265 13060.433
5763 200407 13710.265 41164.976 13721.6587 14135.781 13318.93
5763 200408 14135.781 27846.046 13923.023 14135.781 13710.265
5764 200405 12487.791 25782.978 12891.489 13295.187 12487.791
5764 200406 13295.187 39227.071 13075.6903 13444.093 12487.791
5764 200407 13444.093 40668.974 13556.3247 13929.694 13295.187
5764 200408 13929.694 27373.787 13686.8935 13929.694 13444.093
5765 200405 25057.736 51116.196 25558.098 26058.46 25057.736
5765 200406 26058.460 77418.077 25806.0257 26301.881 25057.736
5765 200407 26301.881 79490.979 26496.993 27130.638 26058.46
5765 200408 27130.638 53432.519 26716.2595 27130.638 26301.881
20 rows selected.
5. ratio_to_report函数的介绍
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6 first,last函数使用介绍
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