原因：selinux阻止寫入操作

解決：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
 

SELINUX=enforcing 改為 SELINUX=disabled

儲存並且重啟伺服器：reboot

再次執行命令：select ...  into outfile ...

則執行成功：Query OK, 0 rows affected

注：關閉selinux可能會帶來安全問題暫時還沒有深入研究（建議操作完成後，改回配置檔案）