mysql查看数据库操作记录
MySQL的查询日志记录了所有MySQL数据库请求的信息。无论这些请求是否得到了正确的执行。默认文件名为hostname.log。默认情况下MySQL查询日志是关闭的。生产环境，如果开启MySQL查询日志，对性能还是有蛮大的影响的。另外很多时候，MySQL慢查询日志基本可以定位那些出现性能问题的SQL，所以MySQL查询日志应用的场景其实不多，有点鸡肋的感觉，它跟SQL Server中的profiler有点类似，但是这个不能跟踪某个会话、用户、客户端。它只能对整个数据库进行跟踪。
window 环境下
- 找到my.ini,在下面添加：
log=存放日志的路径/my.log - 保存文件，重启mysql服务，之后就可以在对应目录的下找到my.log文件。
linux环境下
- MySQL中的参数general_log用来控制开启、关闭MySQL查询日志,参数general_log_file用来控制查询日志的位置。所以如果你要判断MySQL数据库是否开启了查询日志，可以使用下面命令。general_log为ON表示开启查询日志，OFF表示关闭查询日志。
mysql> show variables like ‘%general_log%‘;
+------------------+------------------------------+
| Variable_name | Value |
+------------------+------------------------------+
| general_log | OFF |
| general_log_file | /var/lib/mysql/DB-Server.log |
+------------------+------------------------------+
2 rows in set (0.00 sec)
mysql> - 另外，MySQL的查询日志支持写入文件或写入数据表两种形式，这个由参数log_output控制，如下所示：
mysql> show variables like ‘log_output‘;
+---------------+-------+
| Variable_name | Value |
+---------------+-------+
| log_output | FILE |
+---------------+-------+
1 row in set (0.00 sec)
mysql> - 1、开启MySQL查询日志
```
mysql> set global general_log = on;
Query OK, 0 rows affected (0.11 sec)
mysql> show variables like ‘general_log‘;
+---------------+-------+
| Variable_name | Value |
+---------------+-------+
| general_log | ON |
+---------------+-------+
1 row in set (0.02 sec)
mysql>
- 2：关闭MySQL查询日志mysql> show variables like ‘general_log‘;
+---------------+-------+
| Variable_name | Value |
+---------------+-------+
| general_log | ON |
+---------------+-------+
1 row in set (0.01 sec)
mysql> set global general_log=off;
Query OK, 0 rows affected (0.01 sec)
mysql> show variables like ‘general_log‘;
+---------------+-------+
| Variable_name | Value |
+---------------+-------+
| general_log | OFF |
+---------------+-------+
1 row in set (0.00 sec)
mysql>
- 3：设置日志输出方式为表（如果设置log_output=table的话，则日志结果会记录到名为gengera_log的表中，这表的默认引擎是CSV）：mysql> show variables like ‘log_output‘;
+---------------+-------+
| Variable_name | Value |
+---------------+-------+
| log_output | FILE |
+---------------+-------+
1 row in set (0.00 sec)
mysql> set global log_output=‘table‘;
Query OK, 0 rows affected (0.00 sec)
mysql> show variables like ‘log_output‘;
+---------------+-------+
| Variable_name | Value |
+---------------+-------+
| log_output | TABLE |
+---------------+-------+
1 row in set (0.01 sec)
mysql>
- 4.查看查询日志信息。mysql> select * from mysql.general_log;
+---------------------+---------------------------+-----------+-----------+--------------+----------------------------------+
| event_time | user_host | thread_id | server_id | command_type | argument |
+---------------------+---------------------------+-----------+-----------+--------------+----------------------------------+
| 2017-07-06 12:32:05 | root[root] @ localhost [] | 1 | 1 | Query | show variables like ‘general%‘ |
| 2017-07-06 12:32:28 | root[root] @ localhost [] | 1 | 1 | Query | show variables like ‘log_output‘ |
| 2017-07-06 12:32:41 | root[root] @ localhost [] | 1 | 1 | Query | select * from MyDB.test |
| 2017-07-06 12:34:36 | [root] @ localhost [] | 3 | 1 | Connect | root@localhost on |
| 2017-07-06 12:34:36 | root[root] @ localhost [] | 3 | 1 | Query | KILL QUERY 1 |
| 2017-07-06 12:34:36 | root[root] @ localhost [] | 3 | 1 | Quit | |
| 2017-07-06 12:34:51 | root[root] @ localhost [] | 1 | 1 | Query | select * from mysql.general_log |
+---------------------+---------------------------+-----------+-----------+--------------+----------------------------------+
7 rows in set (0.02 sec)
mysql>
```
