Question

我正在对SQL表进行查询，该表具有多个列以及多行数据，并且查询根据查询中给出的条件为每个唯一的第一列和第二列返回一行。

例如，我有下表CC

product  term   bid  offer bidcp offercp
AA       sep14  20    10    x   y
AA       Sep14  15     9    p   q  
BA       Sep14  30    15    as  ps
XY       Sep14  25    15    r   t
XY       Oct14   30   20    t    r
XY       Oct14   25   22    p   q

当我在上表上运行查询时，它应该返回以下数据

product  term   bid  offer bidcp offercp
AA       sep14  20    9      x   q(coming from a record which has lowest offer) 
BA       Sep14  30    15      as  ps
XY       Sep14  25    15      r   t
XY       Oct14  30    20      t    r

当我执行以下查询时，它甚至通过bidcp和offercp将数据分组到CC，并返回几乎所有行，因为offercp和bidcp在一个或另一个中是唯一的方式，但我只希望bidcp和offercp成为bid和offer的假设，假设bid和offer对都是唯一的对于每个产品和术语

select product,term,max(bid) as bid,min(offer) as offer,bidcp,offercp from canadiancrudes where product like '%/%' group by product,term,bidcp,offercp

但是，当我从groupby子句中删除bidcp和offercp时，它给我一个明显的错误

Column 'CC.BidCP' is invalid in the select list because it is not contained in either an aggregate function or the GROUP BY clause.

有更好的解决方法吗？

Answer 1

在这种情况下，您需要2个CTE：

WITH o AS (
      SELECT product,term,offer,offercp, ROW_NUMBER() OVER (PARTITION BY product, term ORDER BY offer ASC) AS rn
      FROM  canadiancrudes where product like '%/%'
)
,   b AS (
      SELECT product,term,bid,bidcp, ROW_NUMBER() OVER (PARTITION BY product, term ORDER BY bid DESC) AS rn
      FROM  canadiancrudes where product like '%/%'
)
    SELECT o.product,o.term,b.bid,o.offer,b.bidcp,o.offercp 
    FROM o
    INNER JOIN b 
      ON o.product=b.product
      AND o.term=b.term
    WHERE o.rn=1
    AND b.rn=1

Answer 2

使用CTE获取最小值，最大值 -

WITH MaxMin_CTE AS (
   SELECT product,term,max(bid) as bid,min(offer) AS Offer
   FROM CC
   GROUP BY product,term)
SELECT * from CC 
INNER JOIN MaxMin_CTE ON CC.product = MaxMin_CTE .product
AND CC.bid= MaxMin_CTE.bid AND CC.Offer = MaxMin_CTE.offer
AND CC.Term = MaxMin_CTE.Term

继承人的SQL小提琴 - http://sqlfiddle.com/#!6/a6588/2

为列的每个值仅返回一行以及不同列中的其他值

2 个答案: