Section 1 - Instruction

We've covered INNER JOIN for matching records, LEFT JOIN for keeping all records from the first table, and chaining multiple joins together. Choosing the correct one is a critical SQL skill.

This lesson will test your ability to select and build the right join for various business needs.

Engagement Message

Ready to put your joining skills to the test?

Section 2 - Practice

Type

Swipe Left or Right

Practice Question

For each business question, swipe to the most appropriate JOIN type.

Labels

  • Left Label: INNER JOIN
  • Right Label: LEFT JOIN

Left Label Items

  • List all products that have been reviewed
  • Show only the students enrolled in a class

Right Label Items

  • List all employees and their assigned laptops, if any
  • Generate a list of all departments, even those without employees
Section 3 - Practice

Type

Multiple Choice

Practice Question

Given a Products table with 10 rows and an Orders table with 50 rows, a query performs FROM Products p LEFT JOIN Orders o ON p.product_id = o.product_id. If 3 of the products have never been ordered, how many rows will the result have?

A. 50 B. 47 C. 10 D. 53

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