尝试编写一条可以给出预期输出的sql

Question

我有一张源表和一张目标表。如果2列的负数为正，则需要插入记录，直到负数变为负数。我正在分享输入和预期输出。

期望记录应插入，直到源表（a-d）列的负数变为负数。

Answer 1

您可以利用

lag

窗口函数和内部查询，如下所示：

-- input data
with your_table as(
select 7256 a, 1 b, 1 c, 256 d from dual union all
select 14632, 2, 2, 1052 from dual union all
select 22428, 3, 3, 1428 from dual union all
select 29864, 4, 4, 1864 from dual union all
select 36472, 5, 5, 8864 from dual union all
select 44699, 6, 6, 15472 from dual union all
select 51467, 7, 7, 16840 from dual union all
select 53067, 8, 8, 23840 from dual union all
select 60371, 9, 9, 25067 from dual union all
select 66171, 10, 10, 32067 from dual
)
-- Actual query
select t.a, t.b, t.c, tt.d, t.a-tt.d as diff from
(select a,b,c,d, COALESCE(lag(a) over (order by a), 0) lag_a
from your_table t) t join
(select a,b,c,d, COALESCE(lag(d) over (order by d), 0) lag_d
from your_table t) tt
on t.a > tt.lag_d and TT.D > T.LAG_A
order by t.a, tt.d

输出：

         A          B          C          D       DIFF
---------- ---------- ---------- ---------- ----------
      7256          1          1        256       7000
      7256          1          1       1052       6204
      7256          1          1       1428       5828
      7256          1          1       1864       5392
      7256          1          1       8864      -1608
     14632          2          2       8864       5768
     14632          2          2      15472       -840
     22428          3          3      15472       6956
     22428          3          3      16840       5588
     22428          3          3      23840      -1412
     29864          4          4      23840       6024
     29864          4          4      25067       4797
     29864          4          4      32067      -2203
     36472          5          5      32067       4405

14 rows selected.