Question

我们假设我们有一份不同地址的订单清单每个订单记录都有自己的状态和服务日期 Status是一个int枚举，例如＆＃34; 1,2,3,4,5,6,7,8,9,10＆＃34;，其中＆＃34; 10＆＃34;意味着提交，＆＃34; 2＆＃34;待定，＆＃34; 3＆＃34;已获批准，＆＃34; 6＆＃34;已完成等我们有一项功能，可以在创建新订单时重复使用先前订单的内容。为此，我们需要找到与当前订单具有相同地址和服务类型的最新订单记录但还有一件事。我们需要根据订单状态找到最新记录。首先，我们感兴趣的是已经完成了＃39;状态。如果没有此类订单，我们希望通过“已批准”的订单查找订单。状态。然后提交＆＃39;等等。

到目前为止，我已经提出了下一个解决方案：

declare @date datetime = '2016-10-18';  
declare @serviceType varchar(20) = 'delivery';  
declare @zipCode int = 99999;  

WITH cte AS (  
  SELECT * FROM Order AS O  
  WHERE O.serviceDate <= @date AND  
  O.serviceType = @serviceType AND  
  O.zipCode = @zipCode)  

/* find order for content re-using */  
SELECT TOP 1 * FROM cte  
WHERE status =   
  CASE   
  WHEN 0 < (SELECT COUNT(1) FROM cte  
  WHERE Status = 6) /* completed */  
  THEN 6  
  WHEN 0 < (SELECT COUNT(1) FROM cte  
  WHERE Status = 3) /* approved */  
  THEN 3  
  WHEN 0 < (SELECT COUNT(1) FROM cte  
  WHERE Status = 2) /* pending */  
  THEN 2  
  WHEN 0 < (SELECT COUNT(1) FROM cte  
  WHERE Status = 10) /* submitted */  
  THEN 10    
  END  
ORDER BY serviceDate DESC;

有更好的（更优化的）解决方案吗？

Answer 1

我假设您的查询返回正确的结果，正确的优先级是6,3,2,1,9,10。相应地更改订单。请尝试以下更清洁的代码。

DECLARE @date datetime = '2016-10-18';  
DECLARE @serviceType varchar(20) = 'delivery';  
DECLARE @zipCode int = 99999;  

    SELECT  TOP (1) *  
    FROM [dbo].[Order] AS O  
    WHERE O.serviceDate <= @date AND  
          O.serviceType = @serviceType AND  
          O.zipCode = @zipCode AND  
          Status  IN (SELECT  Status  FROM [dbo].[Order] M GROUP BY (M.Status  ) HAVING COUNT(*)>=1 )    

          ORDER BY CASE WHEN Status  = 6 THEN 1
              WHEN Status  =2 THEN 2
              when Status  = 3THEN 3
              when Status  = 1 THEN 4
              when Status  = 9 THEN 5
               when Status  = 10 THEN 6 END ASC,
         serviceDate  DESC

Answer 2

经过深思熟虑后，我想出了下一个解决方案。

select top 1 *, 
  CASE 
      WHEN so.WP_GenericStatus = 6 THEN 1
      WHEN so.WP_GenericStatus = 3 THEN 2
      WHEN so.WP_GenericStatus = 2 THEN 3
      WHEN so.WP_GenericStatus = 10 THEN 4
      ELSE 5
  END AS 'Priority'  
  FROM Order AS O
  WHERE O.serviceDate <= @date and 
  O.serviceType = @serviceType and
  O.zipCode = @zipCode 
  ORDER BY 'Priority' ASC, serviceDate DESC

通过应用其他条件选择记录，直到在SQL Server中找到记录

2 个答案: