ABS and MOD in MySQL - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ query_result

intermediate

Output of ABS and MOD with positive numbers

What is the output of the following MySQL query?

SELECT ABS(7), MOD(7, 3);

MySQL

SELECT ABS(7), MOD(7, 3);

A -7, 1

B 7, 0

C 7, 1

D -7, 0

💡 Hint

ABS returns the positive value of a number. MOD returns the remainder of division.

ABS(7) returns 7 because 7 is already positive. MOD(7, 3) returns 1 because 7 divided by 3 leaves remainder 1.

❓ query_result

intermediate

Output of ABS and MOD with negative numbers

What is the output of this MySQL query?

SELECT ABS(-10), MOD(-10, 4);

MySQL

SELECT ABS(-10), MOD(-10, 4);

A -10, 2

B 10, 2

C 10, -2

D -10, -2

💡 Hint

ABS makes numbers positive. MOD returns remainder, always non-negative in MySQL when divisor is positive.

ABS(-10) returns 10. MOD(-10, 4) returns 2 because MySQL MOD returns a non-negative remainder when the divisor is positive.

📝 Syntax

advanced

Identify the syntax error in MOD usage

Which option contains a syntax error in using the MOD function in MySQL?

A SELECT MOD(10);

B SELECT MOD('10', 3);

C SELECT MOD(10, 3);

D SELECT MOD(-10, 3);

💡 Hint

MOD requires exactly two arguments.

MOD function requires two arguments. Option A has only one argument, causing syntax error.

❓ optimization

advanced

Optimizing ABS and MOD in a WHERE clause

Which query is the most efficient to find rows where the absolute value of column 'score' modulo 5 equals 3?

A SELECT * FROM results WHERE MOD(score, 5) = 3 OR MOD(score, 5) = -3;

B SELECT * FROM results WHERE ABS(MOD(score, 5)) = 3;

C SELECT * FROM results WHERE MOD(ABS(score), 5) = 3;

D SELECT * FROM results WHERE MOD(score, 5) = 3;

💡 Hint

MOD in MySQL always returns a non-negative remainder when divisor is positive.

In MySQL, MOD(score, 5) returns values from 0 to 4. So checking MOD(score, 5) = 3 is enough and most efficient.

🧠 Conceptual

expert

Understanding MOD behavior with negative divisor

What is the output of this MySQL query?

SELECT MOD(10, -3), MOD(-10, -3);

MySQL

SELECT MOD(10, -3), MOD(-10, -3);

A -2, -1

B 1, 1

C 1, -1

D 2, 1

💡 Hint

MOD returns remainder with sign of divisor in MySQL.

MOD(10, -3) returns -2 because 10 = floor(10/-3)*(-3) + (-2) i.e., floor(-3.333)=-4, -4*(-3)=12, 10-12=-2. MOD(-10, -3) returns -1 because floor(-10/-3)=floor(3.333)=3, 3*(-3)=-9, -10 - (-9)=-1.