查询MYsql中最后几条记录

有时候我们需要数据库中的实时数据，而这些实时数据又是插入在表最后面的，所以我们需要获取表中最后面的几条记录，怎么操作呢

select * from msg order by id desc limit n ;
那获取数据表中总共有多少条记录呢

select count(*) from msg;

结果如下

mysql> select * from msg order by id desc limit 2 ;

+-----+-------------+--------------+------------+------------+----+-----------+------------+----+-----------+-------+

| id  | terminal_id | msg_time     | gps_status | degree_lon | m1 | s1        | degree_lat | m2 | s2        | speed |

+-----+-------------+--------------+------------+------------+----+-----------+------------+----+-----------+-------+

| 339 | 66666       | 140523093712 | A1         | +113       | 14 | 584765632 | +23        | 5  | 542285184 |     0 |

| 338 | 99999       | 140523093755 | A          | 113        | 55 | 179296880 | 22         | 34 | 86865232  | 50.32 |

+-----+-------------+--------------+------------+------------+----+-----------+------------+----+-----------+-------+

2 rows in set

mysql> select count(*) from msg;

+----------+

| count(*) |

+----------+

|      339 |

+----------+

1 row in set

mysql>