Batch create convenience : Ignore, overwrite, or error if some data has same value on DB?

usability

#1

There should only one food menu for every single date.

I have a single day food create and a weekly one.

Usually in a scenario like this, it is common to throw an error saying that a data already exists.

I am thinking if a user created a single food menu for a day, and decided to use the weekly food menu, there is a chance that it might overlap it.

My question now is:

Is it fine to ignore it and process those that doesn’t exists for convenience? And just give an information/warning message that a certain was ignored because it already exist?

OR

Should I just overwrite it?

But overwriting seems kinda inconvenient if the user forgot that he already made one for that day and overwrote it with the new one.

BUT

Is there by any chance you think they will forgot that they have already made one for a certain day? Or any reason that it really is inconvenient?

** OR **

Just stick to the usual and just throw an error and not process it first?


#2

I think I would expect to see an error that gave me the option to cancel or overwrite.