I have two tables:
我有两张桌子:
mysql> desc myps3t_gameusertrophyinfo;
+-----------+--------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+-----------+--------------+------+-----+---------+----------------+
| id | int(11) | NO | PRI | NULL | auto_increment |
| user_id | int(11) | NO | MUL | NULL | |
| trophy_id | int(11) | NO | MUL | NULL | |
| date | datetime | NO | MUL | NULL | |
| date_read | varchar(100) | NO | | NULL | |
+-----------+--------------+------+-----+---------+----------------+
5 rows in set (0.19 sec)
mysql> show index from myps3t_gameusertrophyinfo;
+---------------------------+------------+------------------------------------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+
| Table | Non_unique | Key_name | Seq_in_index | Column_name | Collation | Cardinality | Sub_part | Packed | Null | Index_type | Comment |
+---------------------------+------------+------------------------------------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+
| myps3t_gameusertrophyinfo | 0 | PRIMARY | 1 | id | A | 4004589 | NULL | NULL | | BTREE | |
| myps3t_gameusertrophyinfo | 0 | user_id | 1 | user_id | A | 7686 | NULL | NULL | | BTREE | |
| myps3t_gameusertrophyinfo | 0 | user_id | 2 | trophy_id | A | 4004589 | NULL | NULL | | BTREE | |
| myps3t_gameusertrophyinfo | 1 | myps3t_gameusertrophyinfo_403f60f | 1 | user_id | A | 7686 | NULL | NULL | | BTREE | |
| myps3t_gameusertrophyinfo | 1 | myps3t_gameusertrophyinfo_61a683d8 | 1 | trophy_id | A | 22624 | NULL | NULL | | BTREE | |
| myps3t_gameusertrophyinfo | 1 | idx_gameusertrophyinfo_date | 1 | date | A | 4004589 | NULL | NULL | | BTREE | |
+---------------------------+------------+------------------------------------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+
7 rows in set (0.06 sec)
mysql> desc myp
