Mysql 按行计算给定值的外观
我有一个名为Mysql 按行计算给定值的外观,mysql,count,Mysql,Count,我有一个名为private\u message的表,其中包含以下字段:sender和receiver 我想知道某个特定发件人向给定的人发送消息的次数,例如: **Name** **Times** David 5 Michael 2 John 1 试试这个: SELECT sender as 'From', receiver as 'To', count(receiver) as 'Times' FROM private_messag
private\u message
的表,其中包含以下字段:sender
和receiver
我想知道某个特定发件人向给定的人发送消息的次数,例如:
**Name** **Times**
David 5
Michael 2
John 1
试试这个:
SELECT
sender as 'From',
receiver as 'To',
count(receiver) as 'Times'
FROM private_message
GROUP BY sender, receiver
结果可能类似于:
From To Times
David Emil 5
Michael Møller 2
John Ringgaard 1
Emil Ravinder 1
发送方和接收方是否也在您的私有消息表中的表或字段中?只要拿出你的桌子,你就做到了非常感谢,它工作得非常好