IS NULL and IS NOT NULL in MySQL - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to select all rows where the column 'email' has no value (is NULL).

MySQL

SELECT * FROM users WHERE email [1];

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

A= NULL

BIS NULL

CIS NOT NULL

D!= NULL

Attempts:

3 left

💡 Hint

Common Mistakes

Using '= NULL' instead of 'IS NULL'

Using '!=' or '<>' to check for NULL

To check if a column has no value, use IS NULL. Using = NULL does not work in SQL.

2fill in blank

medium

Complete the code to select all rows where the column 'phone' has a value (is NOT NULL).

MySQL

SELECT * FROM contacts WHERE phone [1];

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

AIS NOT NULL

B!= NULL

CIS NULL

D= NULL

Attempts:

3 left

💡 Hint

Common Mistakes

Using '= NULL' or '!= NULL' which do not work for NULL checks

Using 'IS NULL' instead of 'IS NOT NULL'

To find rows where a column has a value, use IS NOT NULL.

3fill in blank

hard

Fix the error in the code to correctly select rows where 'address' is NULL.

MySQL

SELECT * FROM customers WHERE address [1];

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

A!= NULL

BIS NOT NULL

C= NULL

DIS NULL

Attempts:

3 left

💡 Hint

Common Mistakes

Using '=' or '!=' operators with NULL

Confusing IS NULL and IS NOT NULL

Using = NULL causes an error or no results. Use IS NULL to check for NULL values.

4fill in blank

hard

Fill both blanks to select rows where 'birthdate' is NOT NULL and 'nickname' IS NULL.

MySQL

SELECT * FROM profiles WHERE birthdate [1] AND nickname [2];

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

AIS NOT NULL

BIS NULL

C= NULL

D!= NULL

Attempts:

3 left

💡 Hint

Common Mistakes

Using '= NULL' or '!= NULL' instead of IS NULL or IS NOT NULL

Mixing up IS NULL and IS NOT NULL

Use IS NOT NULL to check for values present and IS NULL to check for missing values.

5fill in blank

hard

Fill all three blanks to select rows where 'email' IS NOT NULL, 'phone' IS NULL, and 'status' IS NOT NULL.

MySQL

SELECT * FROM users WHERE email [1] AND phone [2] AND status [3];

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

AIS NULL

BIS NOT NULL

C!= NULL

D= NULL

Attempts:

3 left

💡 Hint

Common Mistakes

Using '= NULL' or '!= NULL' operators

Confusing which columns should be NULL or NOT NULL

Use IS NOT NULL for columns that must have values and IS NULL for columns that must be empty.