mysql> select * from test into outfile '/tmp/test_out.txt' fields terminated by ',' optionally enclosed by '"';
ERROR 1290 (HY000): The MySQL server is running with the --secure-file-priv option so it cannot execute this statement

报错原因：
secure_file_priv设置了指定目录，需要在指定的目录下进行数据导出

mysql> show variables like '%secure%';
+--------------------------+-----------------------+
| Variable_name            | Value                 |
+--------------------------+-----------------------+
| require_secure_transport | OFF                   |
| secure_auth              | ON                    |
| secure_file_priv         | /var/lib/mysql-files/ |
+--------------------------+-----------------------+
3 rows in set (0.27 sec)

mysql> select * from test into outfile '/var/lib/mysql-files/test_out.txt' fields terminated by ',' optionally enclosed by '"';
Query OK, 5 rows affected (0.21 sec)

如果secure_file_priv参数为空，则需要在配置文件中设置该参数，并重启数据库
[mysql@localhost percona]$ bin/mysqladmin -uroot -S /u01/mysql_data/mysql.sock shutdown -p
Enter password:
2017-03-13T10:38:21.340514Z mysqld_safe mysqld from pid file /u01/mysql_data/localhost.localdomain.pid ended
[1]+  Done                    bin/mysqld_safe --defaults-file=/u01/mysql_data/my.cnf
[mysql@localhost percona]$ vim /u01/mysql_data/my.cnf
[mysqld]
secure_file_priv='/database/percona'

[mysql@localhost percona]$ bin/mysqld_safe --defaults-file=/u01/mysql_data/my.cnf &
[1] 28543
[mysql@localhost percona]$  mysqld_safe Adding '/database/percona/lib/mysql/libjemalloc.so.1' to LD_PRELOAD for mysqld
2017-03-13T10:46:33.142327Z mysqld_safe Logging to '/u01/mysql_data/mysqld_error.log'.
2017-03-13T10:46:33.143853Z mysqld_safe Logging to '/u01/mysql_data/mysqld_error.log'.
2017-03-13T10:46:33.166624Z mysqld_safe Starting mysqld daemon with databases from /u01/mysql_data


secure_file_priv参数说明

这个参数用来限制数据导入和导出操作的效果，例如执行LOAD DATA、SELECT ... INTO OUTFILE语句和LOAD_FILE()函数。这些操作需要用户具有FILE权限。
如果这个参数为空，这个变量没有效果；
如果这个参数设为一个目录名，MySQL服务只允许在这个目录中执行文件的导入和导出操作。这个目录必须存在，MySQL服务不会创建它；
如果这个参数为NULL，MySQL服务会禁止导入和导出操作。这个参数在MySQL 5.7.6版本引入。