Question

我们有一份报告需要将数据获取7天，如下所示：

declare @table table (ProductId int, product nvarchar(255), supplier nvarchar(255), day1 int,  day2 int, day3 int, day4 int, day5 int, day6 int, day7 int)

但问题是我目前运行的7个插入语句几乎相同。

insert @table (ProductId, product, supplier, day1)
select 
   productId,
   product, 
   supplier,
   COUNT(productId)
from 
   @results
where 
   createdDate = @Date   
group by
   CreatedDate, ProductId, Product, supplier

这个插入day1，但是我必须对day2，day3做同样的事情....只是改变@Date

我想要做的是创建一个循环，插入到正确的列中，这取决于当前循环（即处理day1或day2 ......）。

有没有办法动态地将它设置为insert语句的正确列名？

我正在使用：sql server 2008R2

Answer 1

您是否可以尝试使用SQL-Server 2008中的PIVOT函数在一个查询中完成插入操作？

我假设你的日子是连续的，你的专栏是Day1，Day2等。

;WITH Data AS
(   SELECT  ProductID,
            Product,
            Supplier,
            DATEDIFF(DAY, @Date, CreatedDate) + 1 AS DayNumber,
            ProductID AS [Counter]
    FROM    @Results
    WHERE   CreatedDate BETWEEN @Date AND DATEADD(DAY, 7, @Date)
)
INSERT @table (ProductID, Product, Supplier, Day1, Day2, Day3, Day4, Day5, Day6, Day7)
SELECT  *
FROM    Data
        PIVOT
        (   COUNT([Counter])
            FOR DayNumber IN ([1], [2], [3], [4], [5], [6], [7])
        ) pvt

Answer 2

如果您在处理SQL问题时发现自己要求使用循环，那么您可能没有使用适当的思维模式来解决问题。

下面的起点。

SELECT  productId
      , product
      , supplier
      , day1 = SUM(CASE WHEN createdDate = @date THEN 1 ELSE 0 END)
      , day2 = SUM(CASE WHEN createdDate = DATEADD(d,1,@date) THEN 1 ELSE 0 END)...   


FROM    @results
WHERE   createdDate >= @Date
GROUP BY CreatedDate
      , ProductId
      , Product
      , supplier

Answer 3

我建议你不要这样做，而是将目标表结构改为另外两个名为day_count的列，它存储当天的计数和createdDate

create table @table (productId int,product int, supplier int,
    createdDate date,day_count int)

可以使用下面的查询填充此表

insert @table (ProductId, product, supplier,createdDate, day_count)
select 
   productId,
   product, 
   supplier,
   createdDate,
   COUNT(productId)
from 
   @results
where 
   createdDate between @Date and dateadd(dd, 7, @Date)
group by
   CreatedDate, ProductId, Product, supplier

然后使用以下查询获得所需的输出

 declare @startDate date ='2012-07-02';
 with cte as(
select productId ,product , supplier ,createdDate, datediff(dd,
    @startDate,createdDate)+1 [day_num],
    day_count from #tmp)
 select productId ,product , supplier ,createdDate , 
 case when day_num=1 then day_count end [day1],
 case when day_num=2 then day_count end [day2],
 case when day_num=3 then day_count end [day3],
 case when day_num=4 then day_count end [day4],
 case when day_num=5 then day_count end [day5],
 case when day_num=6 then day_count end [day6],
 case when day_num=7 then day_count end [day7]
  from cte

SQL - 使用while循环插入（列名取决于循环）

3 个答案: