Question

我有一个包含event_id，eventname，date，time，location，user_id的表格。每个用户ID可以有多个事件ID。我想查询最高事件ID，例如user id = 30。怎么办呢？

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

Php MySQL查询获取特定用户ID的最大事件ID

3 个答案: