SQL - 选择最小行

Question

我如何获得这些线条（相同的线条具有最小的操作，并且它不总是2）：

从这个？

这是我的选择：

select SCR.order_number, SCR.product_code, REL.operation, REL.quantity
from scrDATA as SCR INNER JOIN 
     relBDE as REL ON SCR.order_number = REL.order_number

我需要为order_number和product_code计算一个部分（例如order_number FA36001607为1500件，order_number FP7201127为5件。

Answer 1

似乎这样可行：

select SCR.order_number, SCR.product_code, MIN(REL.operation), REL.quantity
from scrDATA as SCR INNER JOIN 
     relBDE as REL ON SCR.order_number = REL.order_number
GROUP BY SCR.order_number, SCR.product_code, REL.quantity

Answer 2

我认为这是您需要的查询：

select SCR.order_number, SCR.product_code, REL.operation, REL.quantity
from scrDATA as SCR 
INNER JOIN relBDE as REL ON SCR.order_number = REL.order_number
where REL.operation = 
    (select MIN(REL.operation)
    from scrDATA as SCR 
    INNER JOIN relBDE as REL ON SCR.order_number = REL.order_number)

Answer 3

类似的东西：

select SCR.order_number, SCR.product_code, REL.operation, SUM(REL.quantity)
FROM scrDATA as SCR
INNER JOIN relBDE as REL ON SCR.order_number = REL.order_number,
( SELECT SCR2.order_number, MIN(REL2.operation) AS operation
                 FROM scrDATA as SCR2
                 INNER JOIN relBDE as REL2 ON SCR2.order_number = REL2.order_number
                 GROUP BY SCR2.order_number) AS SCR_OP 
WHERE SCR.order_number = SCR_OP.order_number 
  AND SCR.operation = SCR_OP.operation
GROUP BY SCR.order_number, SCR.product_code, REL.operation