Question

我有一个交易库存数据库。它有销售和收据。我希望在销售时将库存销售与最后成本相匹配。我正在尝试编写SQL查询，但无法确定如何执行子查询或正确连接

数据看起来像这样：

STOCKCODE  DATE   TYPE    QTY  UNIT_VALUE  TOTAL_VALUE
ABC123     01/Dec RECEIPT 10   100.00      1000.00
ABC123     02/Dec SALES   -8   120.00       960.00
ABC123     03/Dec RECEIPT 10   110.00      1100.00
ABC123     04/Dec SALES  -12   120.00      1440.00

所以目前的最后成本是110.00美元。但我希望在12月02日售出8个单位（即100.00美元）时找到最后成本

Answer 1

我认为使用apply运算符可以在这里工作：

select t.*, oa.last_value
from yourtable t
outer apply (
   select top(1) unit_value as last_value
   from yourtable y
   where t.stockcode = y.stockcode
   and y.type = 'RECEIPT'
   and y.[date] < t.[date]
   order by y.[date] DESC
   ) oa

我不确定[type]是否在这个逻辑中起作用，我怀疑它确实如此。

下面有一个查询usg coalesce（）的小附加内容：请参阅SQL Fiddle Demo

CREATE TABLE yourtable 
    ([STOCKCODE] varchar(6), [DATE] datetime, [TYPE] varchar(7), [QTY] int, [UNIT_VALUE] int, [TOTAL_VALUE] int)
;

INSERT INTO yourtable 
    ([STOCKCODE], [DATE], [TYPE], [QTY], [UNIT_VALUE], [TOTAL_VALUE])
VALUES
    ('ABC123', '2001-12-01 00:00:00', 'RECEIPT', 10, 100.00, 1000.00),
    ('ABC123', '2001-12-02 00:00:00', 'SALES', -8, 120.00, 960.00),
    ('ABC123', '2001-12-03 00:00:00', 'RECEIPT', 10, 110.00, 1100.00),
    ('ABC123', '2001-12-04 00:00:00', 'SALES', -12, 120.00, 1440.00)
;

查询1 ：

select t.*, coalesce(oa.last_value,unit_value) last_value
from yourtable t
outer apply (
   select top(1) unit_value as last_value
   from yourtable y
   where t.stockcode = y.stockcode
   and y.type = 'RECEIPT'
   and y.[date] < t.[date]
   order by y.[date] DESC
   ) oa

<强> Results ：

| STOCKCODE |                 DATE |    TYPE | QTY | UNIT_VALUE | TOTAL_VALUE | last_value |
|-----------|----------------------|---------|-----|------------|-------------|------------|
|    ABC123 | 2001-12-01T00:00:00Z | RECEIPT |  10 |        100 |        1000 |        100 |
|    ABC123 | 2001-12-02T00:00:00Z |   SALES |  -8 |        120 |         960 |        100 |
|    ABC123 | 2001-12-03T00:00:00Z | RECEIPT |  10 |        110 |        1100 |        100 |
|    ABC123 | 2001-12-04T00:00:00Z |   SALES | -12 |        120 |        1440 |        110 |

查找上一次上次费用

1 个答案: