There might be a really obvious solution to my question, but I am stuck and did not manage find out what I am doing wrong, so you guys might tell me.
I am not able to create a nullable stored column for my expression using the DATE_ADD function in MySQL 8.
See the following example:
ADD COLUMN `test` TIMESTAMP GENERATED ALWAYS AS (DATE_ADD(col1, INTERVAL col2 HOUR)) STORED NULL;
col1 is TIMESTAMP and col2 is INT
MySQL does not complain, but just converts the expression to
(`col1` + interval `col2` hour)
And the resulting is not nullable as well.