Question

What is the purpose of using an inner join in SQL?

1) To connect all three tables
2) To avoid getting a Cartesian product
3) To filter the results based on a condition
4) To perform calculations on the joined tables

Answer 1

An inner join in SQL is used to filter results based on a related condition between two or more tables, primarily to match rows with corresponding values in a joint column.

Step-by-step explanation:

The purpose of using an inner join in SQL is primarily to filter the results based on a condition. Specifically, an inner join connects rows from two or more tables based on a related column between them, often a primary key in one table that matches a foreign key in another. It does not inherently connect all three tables unless specifically written to do so, and while it does help avoid getting a Cartesian product that would result from a cross join, its main purpose is not to avoid Cartesian products but to combine rows that have matching values in the columns being joined.

Lastly, although an inner join can be used as part of a broader query that performs calculations on the joined tables, the join itself does not perform calculations.