12.2.3. JOIN – Combine Multiple Tables

Try these first

1. 1.

   What does the JOIN operation do in SQL?

   Hint

   Think about connecting pieces of data together.

2. 2.

   What type of JOIN returns all records from the left table?

   Hint

   Which JOIN includes all from the left side?

3. 3.

   What is the purpose of a JOIN in SQL?

   • Combine data from multiple tables
   • Delete data from a table
   • Update records in a table

   Hint

   Consider how you get information from different tables at once.

4. 4.

   True or False: An INNER JOIN returns all rows from both tables, regardless of matching data.

   • True
   • False

   Hint

   Think about what INNER means in terms of overlap.

5. 5.

   Given three tables: users, orders, and payments, write a query that retrieves all users who made payments along with their order details. Use appropriate JOINs.

   Hint

   Ensure you correctly link all three tables based on their respective foreign keys.

6. 6.

   Describe a scenario where you might prefer using FULL JOIN over INNER JOIN and explain why.

   Hint

   Think about comprehensiveness in reporting.