每個唯一一組customer_id，product_id和max的需要字段table_id

Question

我有一個包含大約7列的表，其中包含一個包含XML的字段。

有多個客戶ID，每個客戶ID可能有多個產品ID。

對於客戶ID和產品ID的每個唯一組合，都有多個表ID（稱爲edw_policy_data_id）。

我需要獲取與客戶ID和產品實例ID的每個唯一組合對應的max edw_policy_data_id的XML。

最後，我需要限制日期範圍內的內部查詢。

我目前的查詢看起來像這樣;我現在返回的列數多於我現在需要的數量，並排序它們以調試查詢。我還沒能用max（）做任何有意義的事情。

select edw_policy_data_id, e.customer_id, e.product_instance_id, policy_data_xml 
    FROM [DB].[dbo].[EDW_POLICY_DATA] e 
inner join (SELECT distinct customer_id, product_instance_id 
    FROM [DB].[dbo].[EDW_POLICY_DATA] 
    where created_date > '12/1/2011' 
    and created_date < '12/27/2011 17:16:00') d 
    on e.customer_id = d.customer_id and e.product_instance_id = d.product_instance_id 
order by customer_id, product_instance_id, edw_policy_data_id 

結果是這個樣子：

edw_policy_data_id  e.customer_id e.product_instance_id policy_data_xml 
1      100    200      xml 
2      100    200      xml 
3      100    201      xml 
4      101    203      xml 
5      101    203      xml 

我需要的結果看起來是這樣的調試 - 注意，只爲每個唯一CUSTOMER_ID/product_instance_id組合最大edw_policy_data_id存在。

edw_policy_data_id  e.customer_id e.product_instance_id policy_data_xml 
2      100    200      xml 
3      100    201      xml 
5      101    203      xml 

最後，我要的是每個MAX（edw_policy_id）的XML/CUSTOMER_ID/product_instance_ID組合。

我看着this question的迴應：沒有快樂。

Answer 1

這是您的查詢的修改版本，應該給你你需要什麼：

select MAX(edw_policy_data_id), e.customer_id, e.product_instance_id, policy_data_xml 
    FROM [DB].[dbo].[EDW_POLICY_DATA] e 
inner join (SELECT distinct customer_id, product_instance_id 
    FROM [DB].[dbo].[EDW_POLICY_DATA] 
    where created_date > '12/1/2011' 
    and created_date < '12/27/2011 17:16:00') d 
    on e.customer_id = d.customer_id and e.product_instance_id = d.product_instance_id 
GROUP BY customer_id, product_instance_id, policy_data_xml 
order by customer_id, product_instance_id, MAX(edw_policy_data_id) 

注意已更改的作品：

1. 獲取最大edw_policy_data_id：select MAX(edw_policy_data_id), ...
2. 按照customer_id,product_in的不同組合對結果進行分組GROUP BY customer_id, product_instance_id, policy_data_xml
3. ORDER BY需要相應的更改，以適應變化：stance_id，並policy_data_xmlORDER BY customer_id, product_instance_id, MAX(edw_policy_data_id)

Answer 2

嘗試：

select edw_policy_data_id, customer_id, product_instance_id, policy_data_xml 
FROM [DB].[dbo].[EDW_POLICY_DATA] 
where edw_policy_data_id in 
(SELECT max(edw_policy_data_id) 
FROM [DB].[dbo].[EDW_POLICY_DATA] 
where created_date > '12/1/2011' and created_date < '12/27/2011 17:16:00' 
group by customer_id, product_instance_id) d 

Answer 3

也CTE版本可能（因爲你有一個tsql標籤）

DECLARE @create_from DATETIME = '12/1/2011 00:00:00' ; 
DECLARE @create_to DATETIME = GETDATE() ; 


WITH cte 
      AS (
       SELECT 
       row_number() OVER (PARTITION BY product_instance_id , 
            customer_id ORDER BY edw_policy_data_id DESC) AS rn , 
       edw_policy_data_id , 
       e.customer_id , 
       e.product_instance_id , 
       policy_data_xml 
       FROM 
       [DB].[dbo].[EDW_POLICY_DATA] e 
       INNER JOIN [DB].[dbo].[EDW_POLICY_DATA] d 
       ON e.customer_id = d.customer_id 
        AND e.product_instance_id = d.product_instance_id 
       WHERE 
       d.created_date > @create_from 
       AND d.created_date < @create_to 
      ) 
     SELECT 
     * 
     FROM 
     cte 
     WHERE 
     rn = 1 

- 沒有任何版本加入：

DECLARE @create_from DATETIME = '12/1/2011 00:00:00' ; 
DECLARE @create_to DATETIME = GETDATE() ; 

WITH cte 
      AS (
       SELECT 
       row_number() OVER (PARTITION BY product_instance_id , 
            customer_id ORDER BY edw_policy_data_id DESC) AS rn , 
       edw_policy_data_id , 
       customer_id , 
       product_instance_id , 
       policy_data_xml 
       FROM 
       [DB].[dbo].[EDW_POLICY_DATA] 
       WHERE 
       created_date BETWEEN @create_from AND @create_to 
      ) 
     SELECT 
     * 
     FROM 
     cte 
     WHERE 
     rn = 1