Should junction tables have more than one primary keys from another identifying table?

Question

Here\'s an example: Originally I have 3 tables. Table B references Table A. So now Table B has two primary keys. One used as the original primary key and the other one to en

Answer 1

each table should only have one primary key which is only about this table. If you then want a second column in Table A containing the values of the table B primary key thats find. Just set up a second index to get performance if requires