[Lee_K]

Not exactly sure if this is the right place or not so please move it if not!

I'm still new to all this and have a few questions about CSV files.
So i've set up a MySQL database and uploaded a few CSV files onto seperate tables. Basically so that I can retrieve a few things.
Everything has worked fine but if I was to have an updated CSV file, could I upload it to overwrite the existing data of that table? But only where new data has been added? So basically any old stuff that isn't listed in the new CSV file isn't deleted. Is that possible?
Also, if I was to make a new column on 1 of those tables, and then upload the new CSV file that doesn't have that column on it, would I lose the column that I created aswell?

Apologies if that makes no sense! It might also sound like a really stupid question but like I said i'm still new to all this!

Thanks!