I would like to know how to write a query that will pull data from two tables. The first table called 'personal details' has a column called 'userid' which is the same column in the 'testscores' table - in this table it is called 'id'

I want the 'firstname' and 'surname' from the 'personaldetails' table and the 'testscore' from the 'testscores' table.