mysql - 1 优化多条 SQL 请求

Question

我有一个小问题，我有这 3 个 SQL 请求，我想知道是否可以在 1 个请求中优化它们。

我的 3 个 sql 请求：

SELECT FAI, COUNT( FAI ) AS deferred_count
FROM  `email_errors` 
WHERE STATUS =1
GROUP BY FAI
-------------------------------------------
SELECT FAI, COUNT( FAI ) AS sent_count
FROM  `email_errors` 
WHERE STATUS =0
GROUP BY FAI
-------------------------------------------
SELECT FAI, COUNT( FAI ) AS Bounced_count
FROM  `email_errors` 
WHERE STATUS =2
GROUP BY FAI

因此，如果可能的话，我会尝试获取一个包含 4 列结果的输出表FAI|deferred_count|sent_count|bounced_count

我不知道是否可以根据请求通过“FAI”加入？

Answer 1

SELECT FAI, 
       sum( status = 0 ) AS send_count,
       sum( status = 1 ) AS deferred_count,
       sum( status = 2 ) AS Bounced_count
FROM  `email_errors` 
GROUP BY FAI