发布于 2016-03-26 10:46:31 | 184 次阅读 | 评论: 0 | 来源: 网友投递

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Oracle关系数据库管理系统

Oracle Database,又名Oracle RDBMS,或简称Oracle。是甲骨文公司的一款关系数据库管理系统。到目前仍在数据库市场上占有主要份额。


本文介绍下,oracle中排名函数的用法,通过实例学习oracle排名函数的具体用法,有需要的朋友可以参考下

在oracle中,有rank,dense_rank,row_number,以及分组排名partition。

说明:

rank:排名会出现并列第n名,它之后的会跳过空出的名次,例如:1,2,2,4
dense_rank:排名会出现并列第n名,它之后的名次为n+1,例如:1,2,2,3
row_number:排名采用唯一序号连续值,例如1,2,3,4
partition:将排名限制到某一分组

格式:
 

row_number() over(partition by bb.channel_name order by sum(aa.dk_serv_num) desc nulls last) p1_rank1,
row_number() over(order by sum(aa.dk_serv_num) desc nulls last) rank1,
dense_rank() over(order by nvl(sum(aa.dk_serv_num), 0) desc) rank2,
rank() over(order by sum(aa.dk_serv_num) desc nulls last) rank3

例子:


procedure GetCompetitionRanking(p_UserId in integer, p_CompetitionId in integer, v_cursor out CompetitionCursor)
is
v_startDate date;
v_endDate date;
tmp_startDate varchar2(12);
tmp_endDate varchar2(12);
tmp_date date;
v_sql1 varchar2(2000);
v_sql2 varchar2(2000);
v_where varchar2(1000);

v_comTotal integer;
v_groupTotal integer;
v_comRanking integer;
v_groupRanking integer;
begin
select t.start_date, t.end_date into v_startDate, v_endDate from tbl_competition t where t.competition_id = p_CompetitionId;

tmp_date:= v_endDate+1;
tmp_startDate := to_char(v_startDate, 'yyyy-mm-dd');
tmp_endDate := to_char(tmp_date, 'yyyy-mm-dd');

--group personal total
select count(1) into v_groupTotal from tbl_com_group_user a
where a.com_group_id in
(
select b.com_group_id from tbl_com_group_user b where b.user_id = p_UserId
);

-- Competition personal total
select count(1) into v_comTotal from
(
select a.com_group_id from tbl_com_group a where a.competition_id = p_CompetitionId
) a inner join tbl_com_group_user b on a.com_group_id = b.com_group_id;

--user in competition ranking and group ranking
v_where := 't.DATA_TYPE_ID=1 AND t.STATUS=1 AND
t.DATA_DATE_1 >= TO_DATE('||chr(39)||tmp_startDate||chr(39)||','||chr(39)||'yyyy-mm-dd'||chr(39)||') AND
t.DATA_DATE_1 < TO_DATE('||chr(39)||tmp_endDate||chr(39)||','||chr(39)||'yyyy-mm-dd'||chr(39)||') ';

/*select no from
(
select a.USER_ID, dense_rank() over(order by sum(nvl(DATA_NUMBER_2, 0)) desc) no 
from
(
select user_id from tbl_com_group a
left join tbl_com_group_user b on a.com_group_id = b.com_group_id
where a.competition_id = 1
) a left join VM_MASTER_DATA t on a.user_id = t.user_id and t.DATA_TYPE_ID=1 AND t.STATUS=1 AND
t.DATA_DATE_1 >= TO_DATE('2012-10-02','yyyy-mm-dd') AND
t.DATA_DATE_1 < TO_DATE('2012-12-01','yyyy-mm-dd') 
group by a.user_id
order by no desc
) where user_id = 165*/

v_sql1 := 'select no from
(
select a.USER_ID, dense_rank() over(order by sum(nvl(DATA_NUMBER_2, 0)) desc) no 
from
(
select user_id from tbl_com_group a
left join tbl_com_group_user b on a.com_group_id = b.com_group_id
where a.competition_id = '||p_CompetitionId||'
) a left join VM_MASTER_DATA t on a.user_id = t.user_id and '|| v_where||'
group by a.user_id
order by no desc 
) where user_id = '||p_UserId;

dbms_output.put_line(v_sql1);
execute immediate v_sql1 into v_comRanking;
dbms_output.put_line('------------------------------');
--dbms_output.put_line(v_comRanking);

/*select no from
( 
select a.USER_ID, dense_rank() over(order by sum(nvl(DATA_NUMBER_2, 0)) desc) no 
from
(
select a.user_id from tbl_com_group_user a
where a.com_group_id in
(
select b.com_group_id from tbl_com_group_user b where b.user_id = 165
)
) a left join VM_MASTER_DATA t on a.user_id = t.user_id and t.DATA_TYPE_ID=1 AND t.STATUS=1 AND
t.DATA_DATE_1 >= TO_DATE('2012-10-02','yyyy-mm-dd') AND
t.DATA_DATE_1 < TO_DATE('2012-12-01','yyyy-mm-dd') 
group by a.user_id
order by no desc
)
where user_id=165*/

v_sql2 := 'select no from
(
select a.USER_ID, dense_rank() over(order by sum(nvl(DATA_NUMBER_2, 0)) desc) no
from
(
select a.user_id from tbl_com_group_user a
where a.com_group_id in
(
select b.com_group_id from tbl_com_group_user b where b.user_id = '||p_UserId||'
)
) a left join VM_MASTER_DATA t on a.user_id = t.user_id and '|| v_where||'
group by a.user_id
order by no desc 
) where user_id = '||p_UserId;

dbms_output.put_line(v_sql2);
execute immediate v_sql2 into v_groupRanking;
--dbms_output.put_line('------------------------------');
--dbms_output.put_line(v_groupRanking);

if v_comRanking is null then
v_comRanking := v_comTotal;
end if;

if v_groupRanking is null then
v_groupRanking := v_groupTotal;
end if;

open v_cursor for
select v_comTotal CompetitionPersonalTotal, v_groupTotal UserInGroupPersonTotal, v_comRanking UserInCompRanking, v_groupRanking UserInGroupRanking from dual;

exception
when others then
null;
end;


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