MySQL group BY, sorting the largest record of time in each record

MySQL Tutorial group BY, sort the largest record of time in each record

Select A.* from Test A,
(Select Aid, Max (day) Max_day from test Group by aid) b
where A.aid = B.aid and A.day = B.max_day
ORDER BY A.install Desc

Here is the test table, which tests the SQL

CREATE table if not EXISTS ' test ' (
' ID ' int (a) unsigned NOT NULL auto_increment,
' Install ' int (a) unsigned NOT NULL,
' Day ' int (a) unsigned NOT NULL,
' Aid ' int (a) unsigned NOT NULL,
Primary KEY (' ID ')
) Engine=myisam default Charset=utf8 auto_increment=12;

INSERT INTO ' test ' (' ID ', ' Install ', ' Day ', ' aid ') values
(1, 1232, 20080808, 1),
(2, 2321, 20080809, 2),
(3, 1236, 20080810, 3),
(5, 4212, 20080809, 1),
(6, 2312, 20080810, 1),
(7, 1432, 20080811, 1),
(8, 2421, 20080808, 2),
(9, 4245, 20080811, 2),
(10, 5654, 20080810, 2),
(11, 412, 20080808, 3);