解决：CentOS下MySQL执行select ... into outfile ...: Can't create/write to file '...' (Errcode: 13)

原因：selinux阻止写入操作

解决：vi /etc/selinux/config

# This file controls the state of SELinux on the system.
# SELINUX= can take one of these three values:
#     enforcing - SELinux security policy is enforced.
#     permissive - SELinux prints warnings instead of enforcing.
#     disabled - No SELinux policy is loaded.
SELINUX=enforcing
# SELINUXTYPE= can take one of these two values:
#     targeted - Targeted processes are protected,
#     mls - Multi Level Security protection.
SELINUXTYPE=targeted

将：SELINUX=enforcing   改为 SELINUX=disabled

SELINUX=enforcing 改为 SELINUX=disabled

保存并且重启服务器：reboot

再次执行命令：select ...  into outfile ...

则执行成功：Query OK, 0 rows affected

注：关闭selinux可能会带来安全问题暂时还没有深入研究（建议操作完成后，改回配置文件）