mysql - 左连接问题 - 匹配号码

Question

请看下面的 SQL 查询，它计算了 CheckDate 之间的 Yes 和 No 的数量。

关于MatchSales字段 - 它不按我想要的方式工作。它应该找到 D.MobileNO (取决于 CheckDate )匹配到 S.mobile (查看sales表中的所有记录)

SELECT D.Username, 
    SUM(CASE WHEN D.type = 'Yes' AND UNIX_TIMESTAMP(CheckDate) >= $From_timestamp AND UNIX_TIMESTAMP(CheckDate) <= $To_timestamp THEN 1 ELSE 0 END) as Yes, 
    SUM(CASE WHEN D.type = 'No' AND UNIX_TIMESTAMP(CheckDate) >= $From_timestamp AND UNIX_TIMESTAMP(CheckDate) <= $To_timestamp THEN 1 ELSE 0 END) as No, 
    SUM(CASE WHEN S.mobile IS NULL THEN 0 ELSE 1 END) as MatchSales
FROM dairy as D 
   LEFT JOIN (SELECT DISTINCT mobile FROM sales) as S on D.MobileNo = S.mobile
WHERE source = 'Company' 
GROUP BY D.Username

Answer 1

只需将 CASE 中的 Checkdate 条件添加到 where 子句中:

SELECT D.Username,      
      SUM(CASE WHEN D.type = 'Yes' THEN 1 ELSE 0 END) AS Yes,      
      SUM(CASE WHEN D.type = 'No'  THEN 1 ELSE 0 END) AS No,      
      SUM(CASE WHEN S.mobile IS NULL THEN 0 ELSE 1 END) AS MatchSales 
 FROM dairy AS D     
 LEFT JOIN (SELECT DISTINCT mobile FROM sales) AS S ON D.MobileNo = S.mobile 
 WHERE D.source = 'Company'  
 AND   UNIX_TIMESTAMP(D.CheckDate) >= $From_timestamp 
 AND   UNIX_TIMTIMESTAMP(D.CheckDate) <= $To_timestamp 
 GROUP BY D.Username

没有它你将全面扫描乳制品