PHP MySQL查询以获取特定用户ID的事件ID的最大值

Question

I have a single table with event_id , eventname , date , time , location , user_id . Each user Id can have multiple event ids. I want to query for just the highest event id where user id = 30 for example. How can this be done?

Answer 1

SELECT 
    MAX(event_id) as MEvent_id , 
    eventname, 
    date, 
    time, 
    location, 
    user_id 
FROM mytable 
WHERE user_id = 30

Answer 2

这非常简单。

 SELECT MAX(event_id) FROM table WHERE user_id = 30

Answer 3

SELECT  a.*
FROM    tableName a
        INNER JOIN
        (
            SELECT userID, MAX(event_ID) maxID
            FROM tableName
            GROUP BY userID
        ) b ON  a.userID = b.userID AND
                a.event_ID = b.maxID
WHERE   a.userID = 30