MySQL error when trying to add new columns [duplicate] - mysql

Question

This question already has an answer here:
Create table fail in mysql when using CURDATE() as default
(1 answer)
Closed 7 years ago.
Trying to insert new columns into my blog posts table as part of my sites update.
Here is the mysql code I am using:
ALTER TABLE blogposts
ADD (
postType varchar(20),
postDate datetime NOT NULL DEFAULT CURDATE(),
postTime datetime NOT NULL DEFAULT CURTIME()
);
It throws this error though when executed:
#1064 - You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'CURDATE(),
postTime datetime NOT NULL DEFAULT CURTIME()
)' at line 4
I assume that curdate() is the issue, but do not understand why since it is a valid mysql function.
This is not a duplicate of this as was proposed., the solution in that post did not fix my problem and instead threw this error:
#1067 - Invalid default value for 'postDate'
When using code:
ALTER TABLE blogposts
ADD (
postType varchar(20),
postDate datetime NOT NULL DEFAULT CURRENT_TIMESTAMP,
postTime datetime NOT NULL DEFAULT CURTIME()
);
So for reference, this is not a duplicate question it seems.

Answer 1

Default values for DATETIME columns are not available before MySQL Server 5.6.5.
In 5.6.5 and later, the value you specify as default must be CURRENT_TIMESTAMP or an equivalent expression returning a datetime value.
https://dev.mysql.com/doc/refman/5.6/en/timestamp-initialization.html
Because I want them separated out by default for easier calling from the backend.
That seems like a little bit of a frivolous motivation, when you can SELECT TIME(c1) AS teh_time, DATE(c1) AS teh_date if needed, and almost any other operation you wanted to do, like datetime math, time zone conversions or DATE_FORMAT() would require them to be recombined.