重写SQL而不重复参数

我已经编写了下面的查询，但现在我想改进代码，最终的要求是不要重复任何参数两次。有没有一种方法可以在不影响逻辑的情况下重写此sql查询而不重复Flag1和Flag2参数

SELECT 
CASE WHEN  @PARAM1 = 'REV' THEN SUM(NET_INVOICE_REVENUE) ELSE SUM(QUANTITY) END VAL 
FROM 
 PA_TRANS TR 
JOIN 
 PA_SOLD_TO CUST 
ON 
 TR.SOLD_TO_CUSTOMER = CUST.SOLD_TO_CUSTOMER 
WHERE  
 AGREEMENT_NBR = @AGREEMENT_CSV 
AND 
 PART_NUMBER = @PART_NUMBER 
AND 
 CUST.WW_CORP = CASE WHEN (@FLAG1 = 'N' AND @FLAG2 ='N') THEN @WW_CORP ELSE CUST.WW_CORP END 
AND 
 CUST.WW_AFFLIATE = CASE WHEN (@FLAG1 = 'N' AND @FLAG2 ='Y') THEN @WW_AFFLIATE ELSE       CUST.WW_AFFLIATE END 
AND  
   ( DAY >= @A_START_DATE AND  DAY < @A_END_DATE)

谢谢。

---

Mayurika

如果只想提及一次参数，可以使用CTE或子查询。以下是子查询表单：

SELECT (CASE WHEN p_PARAM1 = 'REV' THEN SUM(NET_INVOICE_REVENUE) ELSE SUM(QUANTITY)
        END) as VAL 
FROM (select @PARAM1 as p_param1, @AGREEMENT_CSV as p_AGREEMENT_CSV,
             @PART_NUMBER as p_PART_NUMBER, @FLAG1 as p_FLAG1, @FLAG2 as p_FLAG2,
             @A_START_DATE as p_A_START_DATE, @A_END_DATE as p_A_END_DATE
     ) params CROSS JOIN
     PA_TRANS TR JOIN
     PA_SOLD_TO CUST 
     ON  TR.SOLD_TO_CUSTOMER = CUST.SOLD_TO_CUSTOMER 
WHERE AGREEMENT_NBR = p_AGREEMENT_CSV AND 
      PART_NUMBER = p_PART_NUMBER AND 
      CUST.WW_CORP = CASE WHEN (p_FLAG1 = 'N' AND p_FLAG2 ='N') THEN @WW_CORP ELSE CUST.WW_CORP END AND 
      CUST.WW_AFFLIATE = CASE WHEN (p_FLAG1 = 'N' AND p_FLAG2 ='Y') THEN @WW_AFFLIATE ELSE       CUST.WW_AFFLIATE END AND  
      ( DAY >= p_A_START_DATE AND  DAY < p_A_END_DATE);

---

此问题似乎与主题无关，因为它是关于。您可以在子查询中使用FLAG1和FLAG2。。。。但是出于好奇，有两次有什么问题？有很多方法可以做到，但在这个例子中它们并不真正值得做。您不想重复这些参数的原因是什么？您使用的是什么数据库？谢谢大家。我在一个xml文件中使用这个查询，这个文件标识了什么？将符号标记为参数。我无法用名称映射此文件中传递的参数。每个默认情况下，mark在脚本中按顺序映射到我要传递的参数。谢谢Gordon。它解决了我的问题。