Question

我想知道是否可以使用SQL查询来做到这一点。我有一个名为“数据”的表，其中包含产品名称，日期和销售编号。

我的桌子看起来像这样：

Product         date       Sale

apple           1/1/2019   5
apple           2/1/2019   4
apple           3/1/2019   3
apple           4/1/2019   2
apple           5/1/2019   1
orange          1/1/2019   1
orange          2/1/2019   2
orange          3/1/2019   3
orange          4/1/2019   4
orange          5/1/2019   5
pear            1/1/2019   6
pear            2/1/2019   4
pear            3/1/2019   3
pear            4/1/2019   2
pear            5/1/2019   5
strawberry      1/1/2019   6
strawberry      2/1/2019   3 
strawberry      3/1/2019   7  
strawberry      4/1/2019   4
strawberry      5/1/2019   2

我想设置一个SQL查询来查找在某些2个日期销售量增加的产品。

例如查找所有在3/1/2019的销售编号大于1/1/2019的产品并且应该返回橙色和草莓。

我是编程领域的新手，我们将为您提供帮助。预先感谢！

Answer 1

您可以尝试使用相关子查询

DEMO

select name,sdate,amount from data a where exists 
  (
   select 1 from data b where a.name=b.name and b.sdate in ('1/1/2019','3/1/2019') and b.amount>a.amount
   and a.sdate<b.sdate
  ) 
and a.sdate in ('1/1/2019','3/1/2019')

OUTPUT:

name        sdate               amount
orange      01/01/2019 00:00:00   1
strawberry  01/01/2019 00:00:00   6

Answer 2

DECLARE @FasatDate Date ='3-1-2019'
DECLARE @SecondDate Date ='1-1-2019'

SELECT T1.Product,T1.[date] FasatDate,T1.Sale FasatDateSale,T2.[date] SecondDate,T2.Sale SecondDateSale FROM (
SELECT * FROM DATA AS [DA]
WHERE [DA].[date]=@FasatDate) T1

INNER JOIN  (
SELECT * FROM DATA AS [DA]
WHERE [DA].[date]=@SecondDate)T2
on
t1.Product = t2.Product AND t1.Sale>t2.Sale

Answer 3

您可以以JOIN的身份进行此操作，但我建议：

select t1.*, t2.sales
from t t1 join
     t t2
     on t2.product = t1.product and
        t2.sales > t1.sales
where t1.date = '1/1/2019'
      t2.date = '3/1/2019';

注意：您应该为日期常数使用标准日期格式-'2019-01-03'或'2019-03-01'，具体取决于您的意思。

您也可以使用聚合来完成此操作：

select product
from t
where t.date in ('1/1/2019', '3/1/2019')
group by product
having (sum(case when t.date = '1/1/2019' then sales end) <
        sum(case when t.date = '3/1/2019' then sales end)
       );

SQL查询查找在某些2个日期增加了价值的所有产品

3 个答案: