Question

我有这样的日期

CustId  Frequency  Date
------  ---------  -----
C1        2        20-Jan-2015
C2        3        22-Feb-2015

我必须得到如下所示的输出

C1  20-Jan-2015
C1  20-Jan-2015
C2  22-Feb-2015
C2  22-Feb-2015
C2  22-Feb-2015

任何人都可以帮我解决这个问题。

先谢谢

Answer 1

你需要一个数字表。有多种方法可以生成一个。这是一个明确的方法：

with numbers(n) as (
      select 1 from dual union all select 2 from dual union all select 3 from dual
     )
select d.CustId, d.date + n.n - 1 as date
from data d join
     numbers n
     on d.frequency <= n.n;

如果你想生成一堆数字，一个典型的方法是：

with numbers(n) as (
      select level as n
      from dual
      connect by level <= 365
     )

Answer 2

您可以使用相关的分层查询来生成额外的行（无需创建额外的表格，并确保您的频率不超过这些数字的范围匹配）：

SELECT CustID,
       "Date"
FROM   CustomerFrequencies c,
       TABLE(
         CAST(
           MULTISET(
             SELECT LEVEL
             FROM   DUAL
             CONNECT BY LEVEL <= c.Frequency
           )
           AS SYS.ODCINUMBERLIST
         )
       )

Answer 3

你可以有一个数字表并加入它

select t1.CustId,t1.Date+t2.number as date 
from table t1 inner join numbers t2
on t2.number<=t1.frequency

将聚合计数拆分为行

3 个答案: