How to use SQL statements: create a new field so that the current time is automatically marked every time a new record is inserted?

I found this expression on the Internet and implemented the above functions on mysql (version 5.7) with the local wamp {code ...} but on the server side, I use the same SQL statement {code ...} prompt: invaliddefavaluvaluefor & #039; reg_time & #039; what should I do if the mysql version of the server is 5.0... I found this expression on the Internet and implemented the above functions in mysql (version 5.7) of the local wamp.

alter table account.users add column reg_time datetime not null default now();

However, on the server side, I use the same SQL statement

alter table users add column reg_time datetime not null default now();

Prompt: Invalid default value for 'Reg _ time'
The mysql version on the server is 5.0.
What should I do?

Reply content:

I found this expression on the Internet and implemented the above functions in mysql (version 5.7) of the local wamp.

alter table account.users add column reg_time datetime not null default now();

However, on the server side, I use the same SQL statement

alter table users add column reg_time datetime not null default now();

Prompt: Invalid default value for 'Reg _ time'
The mysql version on the server is 5.0.
What should I do?

ALTER TABLE `users`ADD COLUMN `reg_time`  timestamp NOT NULL ON UPDATE CURRENT_TIMESTAMP

SQL Server uses getdate ()
Mysql should correspond to now ()

The timestamp type field has two attributes: automatic update of insertion time and modification time.