One unique field inside lookup table (both fields as primary key)
First of all, i'm sorry if this is a stupid question, i'm kinda new at this :)
I'm working on a database, part of which looks like this:
useraddress = lookup table, primary key
I'm making a script that lets the user modify/add data in these 3 tables using one form, using mysqli_insert_id to insert the id generated for the user table in the useraddress.userid field. Once user.id has been inserted into userid, the table generates the same addressid for every entry because the combination of data in both fields is the primary key. Is there a way to somehow make the data in addressid unique as well? Is a lookup table the way to go in this case ?