Non-equi joins in SQL - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to join two tables where the employee's salary is greater than the department's budget.

SQL

SELECT e.name, d.department_name FROM employees e JOIN departments d ON e.salary [1] d.budget;

Drag options to blanks, or click blank then click option'

A=

B<

C>

D<=

Attempts:

3 left

💡 Hint

Common Mistakes

Using '=' instead of '>' causes the join to only match equal salaries and budgets.

Using '<' or '<=' will join rows where salary is less than or equal to budget, which is not what we want.

The query joins employees and departments where the employee's salary is greater than the department's budget, so the operator should be >.

2fill in blank

medium

Complete the code to join orders and shipments where the shipment date is on or after the order date.

SQL

SELECT o.order_id, s.shipment_date FROM orders o JOIN shipments s ON s.shipment_date [1] o.order_date;

Drag options to blanks, or click blank then click option'

A>=

B<

C=

D<=

Attempts:

3 left

💡 Hint

Common Mistakes

Using '=' only matches shipment dates exactly equal to order dates.

Using '<' or '<=' would match shipment dates before order dates, which is incorrect.

The join condition requires shipment dates to be on or after order dates, so the operator should be >=.

3fill in blank

hard

Fix the error in the join condition to correctly join products and discounts where the discount start date is before the product release date.

SQL

SELECT p.product_name, d.discount_rate FROM products p JOIN discounts d ON d.start_date [1] p.release_date;

Drag options to blanks, or click blank then click option'

A<

B>

C>=

D=

Attempts:

3 left

💡 Hint

Common Mistakes

Using '>' or '>=' would mean the discount starts after or on the release date, which is wrong.

Using '=' only matches exact dates, missing other valid rows.

The discount start date should be before the product release date, so the operator should be <.

4fill in blank

hard

Fill both blanks to join employees and projects where the employee's experience is between the project's minimum and maximum experience requirements.

SQL

SELECT e.name, p.project_name FROM employees e JOIN projects p ON e.experience [1] p.min_experience AND e.experience [2] p.max_experience;

Drag options to blanks, or click blank then click option'

A>=

B<

C<=

D>

Attempts:

3 left

💡 Hint

Common Mistakes

Using < or > incorrectly reverses the range logic.

Using '=' only matches exact experience values, missing others.

The employee's experience should be greater than or equal to the minimum and less than or equal to the maximum experience required by the project.

5fill in blank

hard

Fill all three blanks to join sales and targets where the sale amount is greater than the target minimum, less than the target maximum, and the sale date is on or after the target start date.

SQL

SELECT s.sale_id, t.target_name FROM sales s JOIN targets t ON s.amount [1] t.min_amount AND s.amount [2] t.max_amount AND s.sale_date [3] t.start_date;

Drag options to blanks, or click blank then click option'

A>

B<

C>=

D<=

Attempts:

3 left

💡 Hint

Common Mistakes

Using <= or >= incorrectly for amount comparisons.

Using < or > for date comparison misses the 'on or after' condition.

The sale amount should be greater than the minimum and less than the maximum target amounts, and the sale date should be on or after the target start date.