之前将mysql的数据版本从5.6升级到了5.7，导入备份的数据库的时候，若时间的默认值为零会报错Error : Invalid default value for ‘comment_date’。

做了记录以备之后遇到。

root@localhost:~# mysql -u root -p
Enter password:
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 14624
Server version: 5.7.30-0ubuntu0.16.04.1 (Ubuntu)
Copyright (c) 2000, 2020, Oracle and/or its affiliates. All rights reserved.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
mysql> set global sql_mode='ONLY_FULL_GROUP_BY,STRICT_TRANS_TABLES,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION'
    -> ;
Query OK, 0 rows affected, 1 warning (0.00 sec)
mysql> commit;
Query OK, 0 rows affected (0.00 sec)
mysql> exit;
Bye
root@localhost:~#

完成之后再重建数据库，就能导入了。