MySQL - How to create a new table that is a join on primary key of two existing tables

CREATE TABLE result AS 
  (SELECT first.*, 
          second.f1, 
          second.f2, 
          second.f3 
   FROM   first 
          INNER JOIN second 
                  ON first.id = second.id);

To get a view, do the same except replace "TABLE" with "VIEW". If you go with the table rather than the view, make sure to add a primary key as that will not be added by default.

If you are sure you have one and exactly one row in both tables for a given primary ID, then this should work:

SELECT
    tablea.field1, tablea.field2, tablea.field3, ... tablea.fieldn, <---- field list
    tableb.field1, tableb.field2, tableb.field3, ... tableb.fieldm  <---- field list
FROM
    tablea, tableb
WHERE
    tablea.primaryID = tableb.primaryID

You might want to omit tablea's and tableb's primary ID field from the field list if you do not actually need them (in this query both will contain the same value due to the tablea.primaryID = tableb.primaryID condition).

The syntax is relatively similar for a VIEW as well.