Question

如果所有客户都包含销售记录，则此查询已经有效。如果该客户没有订单明细记录，则该客户甚至不会出现在以下查询中返回的行集中。当发生这种情况时，我怎么能弥补零？感谢

select  c1.type0 AS type,  NULLIF(c.cnt,0) AS cnt from    
   (select ct.CustomerTypeName AS type0 from customer_type ct) c1    
     LEFT JOIN    
           (select '贵宾会员' As type0, count(c.CustomerCode) AS cnt    
                 from customer c INNER JOIN     


                (select c.CustomerCode, sum(od.NetSales) AS Sales from customer c
                  INNER JOIN orders o ON (c.CustomerCode = o.CustomerCode)    
                  INNER JOIN order_details od ON (o.OrderCode = od.OrderCode),  
                  VIPLevelUpParam v, ActiveParam a    
               where   a.ActiveID = v.LevelUpID  
               AND a.TableName = 'VIPLevelUpParam'   
               AND   TRIM(CAST(CAST(YEAR(c.MemoryDate) AS CHAR(4)) AS VARCHAR(4))) || '-' ||     
                     TRIM(CAST(CAST(MONTH(c.MemoryDate)  AS CHAR(2)) AS VARCHAR(2)))       
                       = '2013-11' 

                  group by c.CustomerCode, v.LevelUpAmount    
                  having sum(od.NetSales) >= v.LevelUpAmount)  c1    
                  ON c.CustomerCode = c1.CustomerCode   

    union       
     select '普通会员' AS type0, count(c.CustomerCode) AS cnt   
      from customer c INNER JOIN  
       (select c.CustomerCode, sum(od.NetSales) AS Sales  from customer c 
              INNER JOIN orders o ON (c.CustomerCode = o.CustomerCode)    
              INNER JOIN order_details od ON (o.OrderCode = od.OrderCode), 
                VIPLevelUpParam v, ActiveParam a    
                where   a.ActiveID = v.LevelUpID 
                  AND a.TableName = 'VIPLevelUpParam' 
                  AND TRIM(CAST(CAST(YEAR(c.MemoryDate) AS CHAR(4)) AS VARCHAR(4))) || '-' ||     
                      TRIM(CAST(CAST(MONTH(c.MemoryDate)  AS CHAR(2)) AS VARCHAR(2)))       
                      = '2013-11'  
                  group by c.CustomerCode, v.LevelUpAmount    
                  having sum(od.NetSales) < v.LevelUpAmount)  c2    
                  ON c.CustomerCode = c2.CustomerCode  
       ) c    
  ON c.type0 = c1.type0    
  group by c1.type0, c.cnt;

Answer 1

您似乎只需要使用LEFT JOIN

在代码片段中：

select c.CustomerCode, sum(od.NetSales) AS Sales from customer c
INNER JOIN orders o ON (c.CustomerCode = o.CustomerCode)    
INNER JOIN order_details od ON (o.OrderCode = od.OrderCode)

尝试使用：

select c.CustomerCode, sum(od.NetSales) AS Sales from customer c
LEFT JOIN orders o ON (c.CustomerCode = o.CustomerCode)    
INNER JOIN order_details od ON (o.OrderCode = od.OrderCode)

如何选择销售量为0的客户（订单明细表中没有记录）

1 个答案: