我试图计算“ticket”列中两个值“1”和“2”的出现次数，但是当我从“where”和“from”添加另一行时出现错误。
“ticket”是一个列，“tickets”是一个表。
SELECT
COUNT(ticket) as child FROM tickets WHERE ticket = 1,
COUNT(ticket) as adult FROM tickets WHERE ticket = 2
GROUP by ticket
最佳答案
SELECT
COUNT(if(ticket = 1,1,NULL)) as child,
COUNT(if(ticket = 2,1,NULL)) as adult FROM tickets where ticket in (1,2)
GROUP by ticket
或
SELECT
sum(if(ticket = 1,1,0)) as child,
sum(if(ticket = 2,1,0)) as adult FROM tickets where ticket in (1,2)
GROUP by ticket
尝试这样
关于mysql - 在一个查询中使用双 where 和 from 的两个计数请求，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/43645687/