Question

我在临时表中得到以下结果：

CountyName  BatchNumber TotalResult
countyA     6294        69
countyA     6295        298
countyB     6295        12
countyC     6294        36
countyC     6295        32

此表在“ BatchNumber”列中将始终包含2个（并且只有2个）值。我想以以下格式获取结果列表：

CountyName  Batch1  Batch2
countyA     69      298
countyB     null    12
countyC     36      32

这在SQL中可行吗？我知道很容易获取最小和最大“ TotalResult”值的扁平列表，但是我想要的是基于最小和最大“ BatchNumber”的“ TotalResult”值。

Answer 1

with data as (
    select min(BatchNumber) as Batch1, max(BatchNumber) as Batch2
    from T
)
select
    CountyName,
    sum(case when BatchNumber = Batch1 then TotalResult end) as Batch1,
    sum(case when BatchNumber = Batch2 then TotalResult end) as Batch2
from T cross apply data
group by CountyName;

sum操作是一种虚拟操作。每个组中只有一个匹配行，您可以轻松使用min或max。但是求和可以让您处理倍数。

Answer 2

这只是条件聚合，但是使用DENSE_RANK而不是列的值：

--Sample data
WITH VTE AS(
    SELECT *
    FROM (VALUES('countyA',6294,69),
                ('countyA',6295,298),
                ('countyB',6295,12),
                ('countyC',6294,36),
                ('countyC',6295,32))V(CountyName,BatchNumber,TotalResult)),
--Solution
DR AS(
    SELECT CountyName,
           BatchNumber,
           TotalResult,
           DENSE_RANK() OVER (ORDER BY BatchNumber ASC) AS DR
    FROM VTE)
SELECT CountyName,
       MAX(CASE DR.DR WHEN 1 THEN TotalResult END) AS Batch1,
       MAX(CASE DR.DR WHEN 2 THEN TotalResult END) AS Batch2
FROM DR
GROUP BY CountyName;

Answer 3

将ROW_NUMBER与透视逻辑一起使用：

WITH cte AS (
    SELECT *, ROW_NUMBER() OVER (PARTITION BY CountyName ORDER BY BatchNumber) rn
    FROM yourTable
)

SELECT
    CountyName,
    MAX(CASE WHEN rn = 1 THEN TotalResult END) AS Batch1,
    MAX(CASE WHEN rn = 2 THEN TotalResult END) AS Batch2
FROM cte
GROUP BY
    CountyName
ORDER BY
    CountyName;

请注意，这不会生成您期望的 exact 输出。但是，对于countyB，它只有一个批号，在报告单个值的位置似乎是任意的。

Answer 4

只是因为我没有看到PIVOT选项

示例

Select *
 From  (
        Select CountyName
              ,Value = TotalResult
              ,Item =  concat('Batch',row_number() over (partition by CountyName order by BatchNumber) )
        From YourTable
       ) src
 Pivot ( max(Value) for Item in ([Batch1],[Batch2]) ) pvt

返回

CountyName  Batch1  Batch2
countyA     69      298
countyB     12      NULL
countyC     36      32

有没有一种方法可以展平此SQL数据集？

4 个答案: