Question

Oracle 11g 如何编写查询以获得所需结果？具体来说，如何加入要求表中的最新记录？

选择标准：最新细节和最新要求

 with 
 detail as (
 select 'TAXI' code, '4920' numb, 1990 dstart, 'BLUE' taxi_name from dual union all
 select 'TAXI' code, '4920' numb, 2000 dstart, 'PINK' taxi_name from dual union all
 select 'TAXI' code, '4920' numb, 2008 dstart, 'CYAN' taxi_name from dual),

 requirement  as (
select 'TAXI' code, '4920' numb,  2 seqno, 2000 rstart,  25,min_age,'CDL',permit from dual union all
select 'TAXI' code, '4920' numb,  4 seqno, 2000 rstart, 27 min_age, 'CAR' permit from dual union all
select 'TAXI' code, '4920' numb,  6 seqno, 2000 rstart, 29 min_age, 'HAZ' permit from dual union all
select 'TAXI' code, '4920' numb,  2 seqno, 2007 rstart, 24 min_age, 'CDL' permit from dual union all
select 'TAXI' code, '4920' numb,  4 seqno, 2007 rstart, 26 min_age, 'VAN' permit from dual union all
select 'TAXI' code, '4920' numb,  6 seqno, 2007 rstart, 28 min_age, 'HAZ' permit from dual

）

select code,numb,taxi_name, dstart, ranking from (
select code, numb, taxi_name,dstart, rank() over (partition by code, numb 
                                            order by dstart desc ) ranking
from detail)
where ranking =1

产量

CODE NUMB  NAME  YEAR    
---- ---- -----  ------- 
TAXI 4920 CYAN   2008 


DESIRED OUTPUT
--------------------------
 code numb name        dstart     sqno    rstart   min_age permit
 TAXI 4920 CYAN       2008       2         2007    24      CDL
 TAXI 4920 CYAN       2008       4         2007    26      VAN
 TAXI 4920 CYAN       2008       6         2007    28      HAZ

Answer 1

嗯，你基本上有这个想法。您只需将其应用于两个表：

select code,numb,taxi_name, dstart, ranking
from (select code, numb, taxi_name,dstart,
             rank() over (partition by code, numb order by dstart desc) as ranking
      from detail
     ) d join
     (select r.*,
             rank() over (partition by code, numb order by rstart desc) as ranking
      from requirement
     ) r
     on d.code = r.code and
        d.ranking = 1 and
        r.ranking = 1

Answer 2

您的完整查询可能是这样的：

 with detail as 
 (
     select 'TAXI' code, '4920' numb, 1990 dstart, 'BLUE' taxi_name from dual union all
     select 'TAXI' code, '4920' numb, 2000 dstart, 'PINK' taxi_name from dual union all
     select 'TAXI' code, '4920' numb, 2008 dstart, 'CYAN' taxi_name from dual
 ),
 requirement  as 
 (
    select 'TAXI' code, '4920' numb,  2 seqno, 2000 rstart,  25 min_age,'CDL' permit from dual union all
    select 'TAXI' code, '4920' numb,  4 seqno, 2000 rstart, 27 min_age, 'CAR' permit from dual union all
    select 'TAXI' code, '4920' numb,  6 seqno, 2000 rstart, 29 min_age, 'HAZ' permit from dual union all
    select 'TAXI' code, '4920' numb,  2 seqno, 2007 rstart, 24 min_age, 'CDL' permit from dual union all
    select 'TAXI' code, '4920' numb,  4 seqno, 2007 rstart, 26 min_age, 'VAN' permit from dual union all
    select 'TAXI' code, '4920' numb,  6 seqno, 2007 rstart, 28 min_age, 'HAZ' permit from dual
)
select code,numb,taxi_name, dstart, seqno, rstart, min_age, permit
from 
(
    select d.code, d.numb, d.taxi_name, d.dstart, rank() over (partition by d.code, d.numb order by d.dstart desc ) ranking,
        seqno, rstart, min_age, permit
    from detail d
    inner join
    (
        select code, numb, seqno, rstart, min_age, permit,
            rank() over (partition by code, numb order by rstart desc ) ranking
        from requirement
     )  r
        on d.code = r.code
        and d.numb = r.numb
        and r.ranking = 1
)
where ranking =1

请参阅SQL Fiddle with Demo

结果是：

| CODE | NUMB | TAXI_NAME | DSTART | SEQNO | RSTART | MIN_AGE | PERMIT |
------------------------------------------------------------------------
| TAXI | 4920 |      CYAN |   2008 |     2 |   2007 |      24 |    CDL |
| TAXI | 4920 |      CYAN |   2008 |     4 |   2007 |      26 |    VAN |
| TAXI | 4920 |      CYAN |   2008 |     6 |   2007 |      28 |    HAZ |

如何在单个查询中使用多个rank（）？

2 个答案: