Challenge: Combining Table Results

Your task will be to combine the employees and contractors tables using the UNION clause.

After that, from the resulting table, you should retrieve only those IDs that are multiples of 2. Also, you need to retrieve the first_name and last_name columns. Use the syntax WHERE id % 2 = 0. For this task, you need to use subqueries in the FROM section just as shown in the example.

As a result, you should have 3 columns: id (an alias for the ID from both tables), first_name, last_name.

Brief Instructions

• Retrieve the id, first_name, and last_name columns.
• In the FROM clause, write two inner queries joined by the UNION clause.
• In the first inner query, select employee_id, first_name, and last_name from the employees table.
  • Assign the alias id to employee_id.
• In the second inner query, select contractor_id, first_name, and last_name from the contractors table.
  • Assign the alias id to contractor_id.
• Assign the alias combined to both inner queries.
• Finally, use a WHERE clause with the condition id % 2 = 0.

id % 2 == 0 checks if id is even. The % operator returns the remainder after division, so if dividing by 2 leaves no remainder, the number is even.