Aggregate functions (COUNT, SUM, AVG, MAX, MIN) in DBMS Theory - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

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

DBMS Theory

SELECT [1](*) FROM employees;

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

AAVG

BSUM

CCOUNT

DMAX

Attempts:

3 left

💡 Hint

Common Mistakes

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

Using AVG or MAX 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 salaries table.

DBMS Theory

SELECT [1](salary) FROM salaries;

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

ASUM

BCOUNT

CAVG

DMIN

Attempts:

3 left

💡 Hint

Common Mistakes

Using COUNT will count rows, not add values.

Using AVG will give average, not total.

The SUM function adds all values in a column.

3fill in blank

hard

Fix the error in the code to find the average age from the people table.

DBMS Theory

SELECT [1](age) FROM people;

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

ACOUNT

BAVG

CSUM

DMAX

Attempts:

3 left

💡 Hint

Common Mistakes

Using SUM or COUNT will not calculate average.

Using MAX returns the highest value, not average.

The AVG function calculates the average value of a column.

4fill in blank

hard

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

DBMS Theory

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

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

AMAX

BSUM

CMIN

DCOUNT

Attempts:

3 left

💡 Hint

Common Mistakes

Using SUM or COUNT instead of MAX or MIN.

Mixing up MAX and MIN functions.

MAX finds the highest value, and MIN finds the lowest value in a column.

5fill in blank

hard

Fill all three blanks to create a query that counts employees, sums their salaries, and finds the average age.

DBMS Theory

SELECT [1](*) AS total_employees, [2](salary) AS total_salary, [3](age) AS average_age FROM employees;

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

ACOUNT

BSUM

CAVG

DMIN

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing up COUNT and SUM functions.

Using MIN instead of AVG for average calculation.

This query uses COUNT to count employees, SUM to add salaries, and AVG to find average age.