IN and NOT IN operators in MySQL - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to select all employees whose department is either 1, 2, or 3.

MySQL

SELECT * FROM employees WHERE department_id [1] (1, 2, 3);

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

AIN

BNOT IN

C=

DLIKE

Attempts:

3 left

💡 Hint

Common Mistakes

Using '=' instead of 'IN' which only compares one value.

Using 'LIKE' which is for pattern matching, not lists.

The IN operator checks if a value matches any value in a list. Here, it selects employees in departments 1, 2, or 3.

2fill in blank

medium

Complete the code to select all products that are not in categories 4, 5, or 6.

MySQL

SELECT * FROM products WHERE category_id [1] (4, 5, 6);

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

ABETWEEN

BNOT IN

C=

DIN

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'IN' instead of 'NOT IN' which would select only those categories.

Using '=' which only compares one value.

The NOT IN operator selects rows where the value is not in the given list. Here, it excludes categories 4, 5, and 6.

3fill in blank

hard

Fix the error in the query to select customers from city 'New York' or 'Los Angeles'.

MySQL

SELECT * FROM customers WHERE city [1] ('New York', 'Los Angeles');

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

ANOT IN

BLIKE

CIN

D=

Attempts:

3 left

💡 Hint

Common Mistakes

Using '=' which only compares one value and causes an error with multiple values.

Using 'LIKE' which is for pattern matching, not lists.

The IN operator is used to check if the city is one of the listed cities. Using '=' would cause an error because it compares only one value.

4fill in blank

hard

Fill both blanks to select orders where the status is not 'shipped' or 'delivered'.

MySQL

SELECT * FROM orders WHERE status [1] ('shipped', 'delivered') AND priority [2] 'high';

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

ANOT IN

BIN

C=

D!=

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'IN' instead of 'NOT IN' in the first blank.

Using '!=' instead of '=' in the second blank.

The first blank uses NOT IN to exclude 'shipped' and 'delivered' statuses. The second blank uses = to select orders with 'high' priority.

5fill in blank

hard

Fill all three blanks to select employees whose role is 'manager' or 'supervisor' and who work in department 10.

MySQL

SELECT * FROM employees WHERE role [1] ('manager', 'supervisor') AND department_id [2] [3];

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

AIN

BNOT IN

C10

D=

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'NOT IN' for roles which would exclude managers and supervisors.

Swapping '=' and '10' positions or missing one of them.

The first blank uses IN to select roles 'manager' or 'supervisor'. The second and third blanks together form = 10 to select department 10.

Practice

1. What does the IN operator do in a MySQL query?

easy

A. Checks if a value is greater than all values in a list

B. Checks if a value is less than all values in a list

C. Checks if a value matches any value in a list

D. Checks if a value is equal to a single value only

Solution

1. Step 1: Understand the purpose of IN operator

   The IN operator is used to test if a value exists within a set of values.

2. Step 2: Compare with other options

   The options describing comparisons with all values (greater or less than all) are incorrect, as IN checks if a value matches any in the list. The option about equality to a single value is also wrong, since IN handles multiple values.

3. Final Answer:

   Checks if a value matches any value in a list -> Option C

4. Quick Check:

   IN operator = check value in list [OK]

Hint: IN means "is in this list"; NOT IN means "not in this list" [OK]

Common Mistakes:

• Confusing IN with equality (=) operator
• Thinking IN checks all values instead of any
• Mixing IN with greater than or less than comparisons

2. Which of the following is the correct syntax to select rows where the column status is either 'active', 'pending', or 'closed'?

easy

A. SELECT * FROM table WHERE status IN ('active', 'pending', 'closed');

B. SELECT * FROM table WHERE status = IN ('active', 'pending', 'closed');

C. SELECT * FROM table WHERE status NOT IN ('active', 'pending', 'closed');

D. SELECT * FROM table WHERE status IN 'active', 'pending', 'closed';

Solution

1. Step 1: Check correct IN syntax

   The correct syntax uses IN followed by parentheses containing a comma-separated list of values.

2. Step 2: Identify errors in other options

   SELECT * FROM table WHERE status = IN ('active', 'pending', 'closed'); has an extra '=' which is invalid. SELECT * FROM table WHERE status NOT IN ('active', 'pending', 'closed'); uses NOT IN which selects rows not matching the list. SELECT * FROM table WHERE status IN 'active', 'pending', 'closed'; misses parentheses around the list.

3. Final Answer:

   SELECT * FROM table WHERE status IN ('active', 'pending', 'closed'); -> Option A

4. Quick Check:

   Correct IN syntax uses parentheses and no '=' [OK]

Hint: IN must be followed by parentheses with values inside [OK]

Common Mistakes:

• Using '=' before IN
• Omitting parentheses around the list
• Confusing IN with NOT IN

3. Given the table employees with a column department, what will this query return?

SELECT name FROM employees WHERE department NOT IN ('HR', 'Finance');

medium

A. Names of employees in HR or Finance departments

B. Names of employees not in HR or Finance departments

C. Names of employees only in HR department

D. Syntax error due to NOT IN usage

Solution

1. Step 1: Understand NOT IN operator

   NOT IN selects rows where the column value is not in the given list.

2. Step 2: Apply to the query context

   The query returns employee names whose department is not 'HR' or 'Finance'.

3. Final Answer:

   Names of employees not in HR or Finance departments -> Option B

4. Quick Check:

   NOT IN excludes listed values [OK]

Hint: NOT IN excludes listed values from results [OK]

Common Mistakes:

• Thinking NOT IN returns only listed values
• Confusing NOT IN with IN
• Assuming syntax error with NOT IN

4. Identify the error in this query:

SELECT * FROM orders WHERE order_status NOT IN 'shipped', 'delivered';

medium

A. Missing parentheses around the list after NOT IN

B. Incorrect use of NOT IN instead of IN

C. order_status should be in quotes

D. No error, query is correct

Solution

1. Step 1: Check syntax of NOT IN usage

   NOT IN must be followed by parentheses containing the list of values.

2. Step 2: Identify missing parentheses

   The query lists values without parentheses, causing syntax error.

3. Final Answer:

   Missing parentheses around the list after NOT IN -> Option A

4. Quick Check:

   NOT IN requires parentheses around values [OK]

Hint: Always use parentheses after IN or NOT IN [OK]

Common Mistakes:

• Omitting parentheses around value list
• Using quotes incorrectly around column names
• Confusing IN and NOT IN usage

5. You want to find customers who have placed orders but exclude those from countries 'USA', 'Canada', and 'Mexico'. Which query correctly uses NOT IN to achieve this?

hard

A. SELECT customer_id FROM orders WHERE country != ('USA', 'Canada', 'Mexico');

B. SELECT customer_id FROM orders WHERE country IN ('USA', 'Canada', 'Mexico');

C. SELECT customer_id FROM orders WHERE country NOT IN 'USA', 'Canada', 'Mexico';

D. SELECT customer_id FROM orders WHERE country NOT IN ('USA', 'Canada', 'Mexico');

Solution

1. Step 1: Understand the goal

   We want customers excluding those from USA, Canada, and Mexico.

2. Step 2: Choose correct NOT IN syntax

   SELECT customer_id FROM orders WHERE country NOT IN ('USA', 'Canada', 'Mexico'); uses NOT IN with parentheses and a list, correctly excluding those countries.

3. Step 3: Identify errors in other options

   SELECT customer_id FROM orders WHERE country IN ('USA', 'Canada', 'Mexico'); includes those countries (wrong). SELECT customer_id FROM orders WHERE country NOT IN 'USA', 'Canada', 'Mexico'; misses parentheses (syntax error). SELECT customer_id FROM orders WHERE country != ('USA', 'Canada', 'Mexico'); uses != with a list, which is invalid syntax.

4. Final Answer:

   SELECT customer_id FROM orders WHERE country NOT IN ('USA', 'Canada', 'Mexico'); -> Option D

5. Quick Check:

   NOT IN with parentheses excludes listed values [OK]

Hint: Use NOT IN with parentheses to exclude multiple values [OK]

Common Mistakes:

• Using != with multiple values
• Omitting parentheses after NOT IN
• Confusing IN and NOT IN