mysql 5.7 启动是提示 [Warning] TIMESTAMP with implicit DEFAULT value is deprecated

os: ubuntu 16.04
db: mysql 5.7.25

2019-03-06T03:27:26.404335Z 0 [Warning] TIMESTAMP with implicit DEFAULT value is deprecated. Please use --explicit_defaults_for_timestamp server option (see documentation for more details).

mysql> show global variables like '%timestamp%';
+---------------------------------+-------+
| Variable_name                   | Value |
+---------------------------------+-------+
| explicit_defaults_for_timestamp | OFF   |
| log_timestamps                  | UTC   |
+---------------------------------+-------+
2 rows in set (0.00 sec)

查看文档后说要设置成这样

# vi /etc/mysql/mysql.conf.d/mysqld.cnf

explicit_defaults_for_timestamp=1

重启 mysql 时没有再提示错误

参考:
https://dev.mysql.com/doc/refman/5.7/en/server-system-variables.html#sysvar_explicit_defaults_for_timestamp