一个查询 SQL 中的双 COUNT

Question

我想在一个查询中同时做这两个 COUNT，这是最好的方法？我想根据 status_id 计算销售和销售线索

SELECT COUNT(status_id) as Leads FROM activities WHERE YEARWEEK(`date`, 1) = YEARWEEK(CURDATE(), 1) AND status_id =5
SELECT COUNT(status_id) as Sales FROM activities WHERE YEARWEEK(`date`, 1) = YEARWEEK(CURDATE(), 1) AND status_id =4

Answer 1

我假设您希望能够将两者区分开来，因此请添加status_id到您的SELECT列表中，然后添加到列表中GROUP。

SELECT status_id, COUNT(status_id) as Leads 
FROM activities 
WHERE YEARWEEK(`date`, 1) = YEARWEEK(CURDATE(), 1) 
AND status_id IN (4,5)
GROUP BY status_id;

根据评论编辑：

我想要一个计数选择 status_id 作为潜在客户，另一个选择作为销售。

那么，您实际上是在寻找条件聚合。您问题中的示例数据和所需结果从一开始就使这一点更加清晰。

SELECT
  SUM(CASE WHEN status_id = 4 THEN 1 ELSE 0 END) AS Leads,
  SUM(CASE WHEN status_id = 5 THEN 1 ELSE 0 END) AS Sales
FROM activities 
WHERE YEARWEEK(`date`, 1) = YEARWEEK(CURDATE(), 1) 
AND status_id IN (4,5)
GROUP BY status_id;