inner-joins-40.psql

/**
There are several types of JOINs, here we are going to go through
the simplest JOIN type which is an INNER JOIN.

Question: What is a JOIN operation?
Answer: Simply put, JOINS allow us to combine multiple tables together.
        The main reason for the different JOIN types is to decide how
        to deal with information only present in one of the joined tables.
An INNER JOIN will result with the set of records that match records from two or more tables.

Example Query:

SELECT * FROM TableA
INNER JOIN TableB
ON TableA.col_match = TableB.col_match;
 */


-- Let's see what customers are in the customer table and the payment table:

SELECT payment.customer_id, payment.payment_id, customer.first_name
FROM payment
INNER JOIN customer
ON payment.customer_id = customer.customer_id;