sql - Oracle 加入双日期范围

Question

我正在尝试将数据放入双重查询的日期范围中。结果应如下所示：

SINGLEDAY       FLAG
01-NOV-2016     1
02-NOV-2016     -
03-NOV-2016     -
04-NOV-2016     1
05-NOV-2016     -

对于我正在使用的天数列表

select (to_date('11.2016','mm.yyyy')+level-1) as SINGLEDAY
from dual
connect by level <= TO_CHAR(LAST_DAY(to_date('11.2016','mm.yyyy')),'DD')

但是如何将我的表 xyz 的内容与结果连接起来？表 xyz 应通过 DATE_OF_SERVICE（日期）列连接。任何帮助将不胜感激。

Answer 1

这基本上是left join您的查询。假设每个日期在表格中最多有一行：

with d as (
      select (to_date('09.2016','mm.yyyy')+level-1) as singleday
      from dual
      connect by level <= TO_CHAR(LAST_DAY(to_date('09.2016', 'mm.yyyy')), 'DD')
     )
select t.singleday,
       (case when t.date_of_service is not null then 1 end) as flag
from d left join
     t
     on d.singleday = t.date_of_service
order by d.singleday;

如果有多个，那么也许你是什么group by：

with d as (
      select (to_date('09.2016','mm.yyyy')+level-1) as singleday
      from dual
      connect by level <= TO_CHAR(LAST_DAY(to_date('09.2016', 'mm.yyyy')), 'DD')
     )
select t.singleday, count(t.date_of_service) as cnt
from d left join
     t
     on d.singleday = t.date_of_service
group by d.singleday
order by d.singleday;