问题与左连接 - 匹配数

Question

请参阅下面的SQL查询，指望它是数量和否CheckDate

之间在MatchSales场 - 它不工作，我怎么想是。它应该找到（取决于CheckDate）匹配S.mobileD.MobileNO（检查所有记录在sales表）

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

只是简单地从CASE添加了checkdate条件where条款：

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 

无它你会全面扫描奶制品

Answer 2

- 我认为这是你如何做到这一点：

SELECT SUM(Yes) AS Yes, SUM(No) AS No 
FROM (
    SELECT D.Username, 
     (CASE WHEN D.type = 'Yes' AND UNIX_TIMESTAMP(CheckDate) >= $From_timestamp AND UNIX_TIMESTAMP(CheckDate) <= $To_timestamp THEN 1 ELSE 0 END) as [Yes], 
     (CASE WHEN D.type = 'No' AND UNIX_TIMESTAMP(CheckDate) >= $From_timestamp AND UNIX_TIMESTAMP(CheckDate) <= $To_timestamp THEN 1 ELSE 0 END) as [No], 
     (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 
) T