Question

我一直致力于CTE，它将根据某些工作项有效地创建发票行。给出：

Create table JobLines (line int, code varchar(10), qty decimal(9,2))  
go

insert into JobLines values (1, '2222A', 1)  
insert into JobLines values (2, '2222B', 3)  
insert into JobLines values (3, '2222A', -1)  
insert into JobLines values (4, '2222C', 2)  
insert into JobLines values (5, '2222D', 1)  
insert into JobLines values (6, '2222B', -1)  
insert into JobLines values (7, '2222A', 2)  
insert into JobLines values (8, '2222B', -1)  
insert into JobLines values (9,'2222A', -1)  
go

我想要一个可以的CTE：

在匹配代码之前，从正线减去每条负线。

结果应为：

Line Code    Quantity 
1    222A    0          
2    222B    1          
4    222C    2          
5    222D    1          
7    222A    1

第1行 - 0（第3行减去）第2 - 1行（减去第6和第8行）第4行 - 没有变化。
第5行 - 没有变化。
第7 - 1行（第9行减去）。

我几次接近。主要问题是我无法获得第2行或第7行的预期结果，因为我无法有效地将需要减去的2行组合在一起。

我的方法是尝试迭代正线，为每个线提取负线。

我正在处理的示例代码：

;with cte_positive_rows as (select line, code, qty
    ,row_number() over (partition by code order by line) code_instance
    ,row_number() over (order by line) row_sequence
from jobLines
where qty > 0
)
,cte_negative_rows as (
    select line, code, qty
    ,row_number() over (partition by code order by line) code_instance
    ,row_number() over (order by line) row_sequence
from jobLines
where qty < 0
)
,cte_iterator as(
--base case - start with line 1 from cte_postive_rows...

select min(base.line) line, base.code
    ,cast(sum(base.qty + neg.qty) as     decimal(9,2)) total_qty
    ,base.code_instance
    ,base.row_sequence, base.row_sequence + 1 as next_row
    from cte_positive_rows base
    inner join cte_negative_rows neg
    on
    neg.row_sequence = base.row_sequence
    and neg.code_instance = base.code_instance
    where base.row_sequence = 1
    group by base.code, base.code_instance, base.row_sequence

    union all

    --iterative case - each line..
    -- the iterative case should returns all the rows that needed modifying

    select row.line, row.code
    ,cast(row.qty + neg.qty as decimal(9,2)) qty, row.code_instance
    ,row.row_sequence
    ,row.row_sequence + 1 as next_row
    from cte_positive_rows row 
    inner join cte_negative_rows neg
    on
    neg.row_sequence = row.row_sequence
    and neg.code_instance = row.code_instance
    inner join cte_iterator cte
    on row.row_sequence = cte.next_row
)

-- get all the modified and non-modifed rows with joins

select pos.line, pos.code, pos.qty, pos.code_instance, pos.row_sequence
from cte_positive_rows pos
left outer join cte_iterator i
on pos.row_sequence = i.row_sequence
where i.row_sequence IS NULL
union all 
select line, code, total_qty, code_instance, row_sequence from cte_iterator
order by row_sequence

不完全出现，结果如上：

1   2222A   0.00    1   1
2   2222B   2.00    1   2
4   2222C   2.00    1   3
5   2222D   1.00    1   4
7   2222A   2.00    2   5

我的梦想可能吗？！

Answer 1

我不确定我是否完全理解您的要求，但这似乎可以满足您的需求：

select line, code, qty + isnull((
    -- get the sum of all negative values...
    select sum(j1.qty)
    from JobLines j1
    where 
        -- ...for the same code, but with a higher line number...
        j1.code = PositiveLines.code and 
        j1.line > PositiveLines.line and 
        j1.qty < 0 and
        -- ...where there is no positive value on a previous line
        not exists (
            select * 
            from JobLines
            where 
                code = j1.code and 
                qty > 0 and 
                line > j1.line)
    ),0)
from
(   
select
    line, code, qty
from
    JobLines
where
    qty > 0
) PositiveLines

迭代CTE解决

我想要一个可以的CTE：

结果应为：

1 个答案: