COUNT, SUM, AVG, MIN, MAX in PostgreSQL - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to count all rows in the employees table.

PostgreSQL

SELECT [1](*) FROM employees;

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

AAVG

BSUM

CCOUNT

DMIN

Attempts:

3 left

💡 Hint

Common Mistakes

Using SUM instead of COUNT will cause an error or wrong result.

Using AVG or MIN does not count rows.

The COUNT function counts the number of rows in a table or group.

2fill in blank

medium

Complete the code to find the total salary from the employees table.

PostgreSQL

SELECT [1](salary) FROM employees;

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

ASUM

BAVG

CMAX

DCOUNT

Attempts:

3 left

💡 Hint

Common Mistakes

Using COUNT will count rows, not add salaries.

Using AVG will give average salary, not total.

The SUM function adds all values in a column, here it adds all salaries.

3fill in blank

hard

Fix the error in the code to get the average age from the users table.

PostgreSQL

SELECT [1](age) FROM users;

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

ACOUNT

BAVG

CSUM

DMIN

Attempts:

3 left

💡 Hint

Common Mistakes

Using SUM or COUNT will not give the average.

Using MIN gives the smallest value, not average.

The AVG function calculates the average value of a column.

4fill in blank

hard

Fill both blanks to find the minimum and maximum price from the products table.

PostgreSQL

SELECT [1](price) AS min_price, [2](price) AS max_price FROM products;

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

AMIN

BMAX

CSUM

DCOUNT

Attempts:

3 left

💡 Hint

Common Mistakes

Swapping MIN and MAX will give wrong results.

Using SUM or COUNT here is incorrect.

MIN finds the smallest value, and MAX finds the largest value in a column.

5fill in blank

hard

Fill all three blanks to get the count of orders, total amount, and average amount from the orders table.

PostgreSQL

SELECT [1](*) AS total_orders, [2](amount) AS total_amount, [3](amount) AS average_amount FROM orders;

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

ACOUNT

BSUM

CAVG

DMIN

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing up SUM and AVG functions.

Using MIN instead of AVG for average.

COUNT(*) counts all orders, SUM(amount) adds all amounts, and AVG(amount) calculates the average amount.