Question

我的表格包含以下列：product_id，customer_id，start_date，end_date，product，product_use。我的目标是找到客户在每个月初和每个月末使用的产品？有任何想法如何在SQL中执行此操作？感谢。

product_id   cust_id    START_DT    END_DT
8398D           8678    12/18/2013  3/10/2014
270B9           8678    2/14/2014   3/16/2014
C0867           8678    3/25/2014   4/1/2014
2F9D2           8678    4/3/2014    5/7/2014
9AE65           8678    4/25/2014   5/6/2014

预期结果

Month    product_begining_of_month     product_end_of_month 
December        8398D                  8398D
January         8398D                  8398D
February        8398D                  8398D and 270B9  
March           8398D and 270B9        C0867
April           2F9D2                  2F9D2 AND 9AE65

Answer 1

您可以选择ID，第一个和最后一个日期作为结果集;然后使用外表查询这些结果，使用日期和customerid的内部表结果选择productId ..

  SELECT CustID, (SELECT product_id FROM CustomerTable CTBL2 WHERE 
 (CustID=INNTBL.CustID and  (TranscationDate=INNTBL.LastmostDate)) AS
LastmostProduct, (SELECT product_id FROM CustomerTable CTBL3 WHERE 
  (CustID=INNTBL.CustID_ and (TranscationDate=INNTBL.FirstDate)) AS FirstProduct 
      FROM 
  (Select CustId, Max(TranscationDate) AS LastmostDate, 
   Min(TranscationDate) as FirstDate FROM CustomerTable as CTBL
   Group by CustId) AS INNTBL

SQL中的领先和滞后

1 个答案: