CASE in SELECT for computed columns in SQL - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create a computed column named 'status' that shows 'Adult' if age is 18 or more, otherwise 'Minor'.

SQL

SELECT name, age, CASE WHEN age [1] 18 THEN 'Adult' ELSE 'Minor' END AS status FROM people;

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

A>=

B<

C=

D!=

Attempts:

3 left

💡 Hint

Common Mistakes

Using '<' instead of '>=' causes incorrect classification.

Using '=' only matches exactly 18, missing older ages.

The CASE statement checks if age is greater than or equal to 18 to label as 'Adult'. Otherwise, it labels as 'Minor'.

2fill in blank

medium

Complete the code to assign 'High' to scores above 80, otherwise 'Low'.

SQL

SELECT student, score, CASE WHEN score [1] 80 THEN 'High' ELSE 'Low' END AS performance FROM results;

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

A<=

B>

C=

D<

Attempts:

3 left

💡 Hint

Common Mistakes

Using '<=' includes scores 80 or below as 'High', which is wrong.

Using '=' only matches exactly 80, missing higher scores.

The CASE checks if score is greater than 80 to assign 'High'. Otherwise, it assigns 'Low'.

3fill in blank

hard

Fix the error in the CASE statement to correctly label 'Pass' for marks 50 or more, else 'Fail'.

SQL

SELECT student, marks, CASE WHEN marks [1] 50 THEN 'Pass' ELSE 'Fail' END AS result FROM exams;

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

A<

B>

C>=

D=

Attempts:

3 left

💡 Hint

Common Mistakes

Using '>' excludes marks exactly 50 from passing.

Using '=' only matches marks exactly 50.

The correct operator is '>=' to include marks equal to 50 as 'Pass'.

4fill in blank

hard

Fill both blanks to classify salary as 'Low' if less than 3000, 'Medium' if between 3000 and 7000, else 'High'.

SQL

SELECT employee, salary, CASE WHEN salary [1] 3000 THEN 'Low' WHEN salary [2] 7000 THEN 'Medium' ELSE 'High' END AS salary_level FROM employees;

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

A<

B>=

C<=

D>

Attempts:

3 left

💡 Hint

Common Mistakes

Using '>=' in the first condition would misclassify salaries.

Using '>' instead of '<=' in the second condition excludes 7000.

The first condition checks if salary is less than 3000 for 'Low'. The second checks if salary is less than or equal to 7000 for 'Medium'. Otherwise, it's 'High'.

5fill in blank

hard

Fill both blanks to classify temperature as 'Cold' below 10, 'Warm' between 10 and 25, and 'Hot' above 25.

SQL

SELECT city, temperature, CASE WHEN temperature [1] 10 THEN 'Cold' WHEN temperature [2] 25 THEN 'Warm' ELSE 'Hot' END AS temp_label FROM weather;

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

A<

B>=

C<=

D>

Attempts:

3 left

💡 Hint

Common Mistakes

Using '>=' instead of '<' in the first condition mislabels temperatures.

Using '>' instead of '<=' in the second condition excludes 25.

The first condition checks if temperature is less than 10 for 'Cold'. The second checks if temperature is less than or equal to 25 for 'Warm'. Otherwise, it's 'Hot'.