`INNER JOIN` is a join that will join only those records from two tables that contain the same values in the column being joined. It will be easier to understand on the git. Please, watch it.

SELECT column1, column2
FROM table1
INNER JOIN table2
ON table1.shared_column= table2.shared_column 

In this section, we are going to work with the `product` database. It contains the following two tables: `product`, `price`. Let's take a look at them closer and learn their connections.

Let's look at the first table - `product`.

In this section, you will learn how to group and work with such data. For this, we will get acquainted with such an operator as GROUP BY. You will also learn how to filter grouped data using the operator HAVING.

In this section, you will learn what nested subqueries are, how to create them, and how to work with them.

In this section, you will learn how you can combine several tables, thus working with one common table, which will simplify the creation of queries.

In this section, you will learn how to combine several tables in different ways, in particular: INNER JOIN, LEFT JOIN, RIGHT JOIN.