如何在一个查询中使用两个 COUNT

Question

我尝试在一个查询中使用多个计数。目前我正在使用下面的查询，它非常适合一个计数。

SELECT  SERVICE, STANDARD=COUNT(SERVICE) 
FROM    INC_  
WHERE CLIENTNUM='WAYFAIRATL'
  AND DROPTIME IS NULL
  AND CANCELLED=0
  AND SERVICE LIKE 'WCMV%'
  AND CONVERT (VARCHAR(5),READYTIME, 114) = '01:00'
GROUP BY SERVICE

我想在选择中添加另一个字段，用于计算INC_.SCHEDATTEMPT is null 的每个服务的订单数。我该怎么做？

Answer 1

类似这样的：

SELECT  
    SERVICE, 
    COUNT(SERVICE) AS STANDARD,
    SUM(CASE WHEN INC_.SCHEDATTEMPT is null THEN 1 ELSE 0 END) AS SCHEDATTEMPTISNULL
FROM    
    INC_  
WHERE 
    CLIENTNUM='WAYFAIRATL' 
    AND DROPTIME IS NULL AND CANCELLED=0 
    AND SERVICE LIKE 'WCMV%' 
    AND CONVERT (VARCHAR(5),READYTIME, 114) = '01:00'
GROUP BY 
    SERVICE