Login system with username and password from different tables, how to select from?

Question

I have searched for quite a while now about the possibility of having two tables (one for username and one for password) but haven't found anything useful.

I have two tables linked together with Primary Key and Foreign Key. One containing the username and one containing the password.

My current code is only for one table, like this:

   $result = mysqli_query($con, "SELECT membersid FROM members
   WHERE user='{$_POST['user']}'
   AND pass='{$_POST['passwd']}'");

Is there anyway I can use like equi joins together with input in my form?

All I got is this:

   $result = mysqli_query($con, "SELECT adminuser.userid, adminpass.passid 
   FROM adminuser, adminpass
   WHERE username='{$_POST['user']}'
   AND password='{$_POST['passwd']}'");

I know it's probably completely wrong, and I searched for an answer but haven't found one, that's why I'm turning here for help.

Is there anyway to solve my problem?

Answer 1

I am not sure, but here's my 0.02 cents. You are missing this.

ON adminuser.userid=adminpass.userid;

Or maybe, this is more easy to understand.

INNER JOIN is used to combine rows from two or more tables, based on a common field between them.

SELECT adminuser.userid, adminpass.passid
FROM adminuser
INNER JOIN adminpass
ON adminuser.userid=adminpass.userid;