sql - 需要显示一个虚拟月份 - Oracle SQL

Question

出于月费报告目的，需要显示如下所述的输出。仅当支付了该月的费用时，才会将数据输入表中，否则该月将不会出现在表中。

在执行查询时

select reg_id, dop,to_char(dop, 'FMMonth,YYYY') Month, status 
  from fees_status
 where dop between ('1-Jul-2012') and ('1-Dec-2012')

输出是

REG_ID  DOP         MONTH           STATUS

AE-8    7/1/2012    July,2012       PAID
AE-8    9/1/2012    September,2012  PAID
AE-8    11/1/2012   November,2012   PAID
AE-8    12/1/2012   December,2012   PAID

出于报告目的，需要输出为

REG_ID  DOP         MONTH           STATUS

AE-8    7/1/2012    July,2012       PAID
AE-8    8/1/2012    August,2012     NOTPAID
AE-8    9/1/2012    September,2012  PAID
AE-8    10/1/2012   October,2012    NOTPAID
AE-8    11/1/2012   November,2012   PAID
AE-8    12/1/2012   December,2012   PAID

有人可以帮助显示上面提到的输出吗？

Answer 1

您可以使用 partition by外连接的扩展来实现这一点。下面是一个例子:

-- sample of data from your question 
SQL> with fees_status(REG_ID, DOP, MONTH1, STATUS) as(
  2    select 'AE-8', to_date('7/1/2012', 'MM/DD/YYYY'), 'July,2012'     ,'PAID' from dual union all
  3    select 'AE-8', to_date('9/1/2012', 'MM/DD/YYYY'), 'September,2012','PAID' from dual union all
  4    select 'AE-8', to_date('11/1/2012', 'MM/DD/YYYY'),'November,2012' ,'PAID' from dual union all
  5    select 'AE-8', to_date('12/1/2012', 'MM/DD/YYYY'),'December,2012' ,'PAID' from dual
  6  ), -- dates
  7  dates(dt) as(
  8    select add_months(to_date('01/01/2012', 'mm/dd/yyyy'), level - 1)
  9      from dual
 10    connect by level <= 12
 11  )
 12  select t.reg_id
 13       , d.dt as dop
 14       , to_char(d.dt, 'fmMonth, YYYY') as month1
 15       , Nvl(t.status, 'NOTPAID')       as status
 16   from fees_status t
 17   partition by (t.reg_id)
 18   right outer join dates d
 19      on (d.dt = t.dop)
 20   where d.dt between (to_date('1-Jul-2012', 'dd-Month-yyyy'))
 21                  and (to_date('1-Dec-2012', 'dd-Month-yyyy'))
 22  ;

REG_ID DOP         MONTH1                STATUS
------ ----------- -------------------- -------
AE-8   01-Jul-12   July, 2012            PAID
AE-8   01-Aug-12   August, 2012          NOTPAID
AE-8   01-Sep-12   September, 2012       PAID
AE-8   01-Oct-12   October, 2012         NOTPAID
AE-8   01-Nov-12   November, 2012        PAID
AE-8   01-Dec-12   December, 2012        PAID

6 rows selected