Question

我有以下数据：

date          product    amount
2013-01-31    a1           100
2013-02-28    a1           200
2013-01-31    b1           700
2013-04-30    b1           100
2013-06-30    b1          1300
2013-03-31    c1            10
2013-07-31    c1            70

是否可以在sql / plsql中创建基于日期填充缺失行的查询？我的意思是我希望获得以下结果：

date          product    amount
 2013-01-31    a1           100
 2013-02-28    a1           200
 2013-01-31    b1           700
*2013-02-28    b1           500*
*2013-03-31    b1           300*
 2013-04-30    b1           100
*2013-05-31    b1           700*
 2013-06-30    b1          1300
 2013-03-31    c1            10
*2013-04-30    c1            25*
*2013-05-31    c1            40*
*2013-06-30    c1            55*
 2013-07-31    c1            70

即。创建缺少日期，重复产品代码并计算金额。

Answer 1

使用LEAD函数和hierarchical查询的组合，可以在单个查询中实现。

演示here。

    SELECT DISTINCT
           ADD_MONTHS (product_date, LEVEL - 1), product, amount + ( (LEVEL - 1) * mul_factor)
      FROM (SELECT product_date, product, amount, next_date,
                   amount_diff / month_diff mul_factor
              FROM (SELECT product_date, product, amount,
                           LEAD (product_date, 1) OVER (PARTITION BY product ORDER BY product_date)
                              AS next_date,
                           MONTHS_BETWEEN (
                              (LEAD (product_date, 1) OVER (PARTITION BY product ORDER BY product_date)),
                              product_date)
                              AS month_diff,
                           LEAD (amount, 1) OVER (PARTITION BY product ORDER BY product_date)
                              AS next_amount,
                             LEAD (amount, 1) OVER (PARTITION BY product ORDER BY product_date)
                           - amount
                              AS amount_diff
                      FROM mytable)
             WHERE next_date IS NOT NULL)
CONNECT BY ADD_MONTHS (product_date, LEVEL - 1) <= next_date
  ORDER BY 2, 1

此处LEAD功能用于获取下一个日期和下一个金额。使用此，可以找到均匀分配金额所需的月份差异，金额和价值差异。稍后在分层查询中使用它来获取开始日期和结束日期之间的所有月份。但这会产生几个重复的行，我似乎无法消除。因此使用了DISTINCT关键字。

输出：

01/31/2013    a1    100
02/28/2013    a1    200
01/31/2013    b1    700
02/28/2013    b1    500
03/31/2013    b1    300
04/30/2013    b1    100
05/31/2013    b1    700
06/30/2013    b1    1300
03/31/2013    c1    10
04/30/2013    c1    25
05/31/2013    c1    40
06/30/2013    c1    55
07/31/2013    c1    70

Answer 2

我假设product_amounts是此表的名称。

declare
  n integer;
  i integer;
  a integer;
  d date;
begin
  for x in
  (
    select *
    from   ( select product,
                    amount,
                    trunc(date, 'MONTH') mon,
                    lead(trunc(date, 'MONTH')) over(partition by product order by date) next_mon,
                    lead(amount) over(partition by product order by date) next_amount,
             from   product_amounts
           )
    where  months_between(next_mon, mon) > 1
  )
  loop
    n := months_between(x.next_mon, x.mon);
    for i in 1 .. n-1
    loop
      d := add_months(x.mon, i);
      a := x.amount + (x.next_amount - x.amount)/n;

      insert into product_amounts(date, product, amount)
      values (last_day(d), x.product, a);
    end loop;
  end loop;

  commit;
end;

填充oracle sql中缺少的行

2 个答案: