Best approach for Legal/Natural can have many Orders
This is an alternative to your solution. I suppose your id columns are just for mysql internal use, so you could have:


person table with id, name, and type which would be a bit or 1 character to say if it is a natural or legal person. This table will connect to order table where you will only need one column - person_id
On natural_person table you remove the name column and connect it to the person table
On legal_person table you remove the name column and connect it to the person table