Inner Join

SELECT
  *
FROM
  albums
JOIN artists ON
  albums.artist_id = artists.id;

In SQL, joins are used to combine rows from two or more tables. The most common type of join in SQL is an inner join.

An inner join will combine rows from different tables if the join condition is true. Let's look at the syntax to see how it works.

1. SELECT * specifies the columns our result set will have. Here, we want to include every column in both tables.
2. FROM albums specifies the first table we are querying.
3. JOIN artists ON specifies the type of join we are going to use as well as the name of the second table. Here, we want to do an inner join and the second table we want to query is artists.
4. albums.artist_id = artists.id is the join condition that describes how the two tables are related to each other. Here, SQL uses the foreign key column artist_id in the albums table to match it with exactly one row in the artists table with the same value in the id column. We know it will only match one row in the artists table because id is the PRIMARY KEY of artists.