mysql - 简单的MYSQL不同选择

Question

如果我有一个包含两列(名称和时间戳)的表，以及一堆具有共享名称的行。如何选择具有相同名称的每组行中的最新行？

谢谢!

Answer 1

SELECT name, MAX(timestamp) FROM Table1 GROUP BY name

编辑:根据评论，请尝试以下操作:

SELECT name, timestamp, col3, col4
FROM   Table1 t1
WHERE  timestamp = (SELECT MAX(t2.timestamp)
              FROM Table1 t2
              WHERE t1.name = t2.name);

<小时/>

由麦克尔添加

没有依赖子查询的版本(应该表现更好)

SELECT 
  t1.name, t1.timestamp, t1.col3, t1.col4
FROM   
  Table1 AS t1
CROSS JOIN (
  SELECT 
    name, MAX(timestamp) AS timestamp
  FROM 
    Table1
  GROUP BY
     name
) AS sq
USING (name,timestamp)