Question

我已经编写了以下查询，但我现在想要优化代码，最终要求是不要重复任何参数两次。有没有办法重写这个SQL查询而不重复Flag1和Flag2参数而不影响逻辑？

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)

感谢。 Mayurika

Answer 1

如果您只想提一次参数，可以使用CTE或子查询。这是子查询形式：

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);

在不重复参数的情况下重写SQL

1 个答案: