MySQL MIN() and MAX() Functions

MySQL MIN() and MAX() Functions

In MySQL, the MIN() and MAX() functions are aggregate functions used to find the smallest and largest values in a column.

•  These functions are very common in reports, analytics, exams, and interviews.

 What are MIN() and MAX()?

• MIN() → returns the lowest value

• MAX() → returns the highest value

• Work on numeric, date, and string columns

• Return one value per group

 They ignore NULL values.

 Basic Syntax

 Simple Examples

Find Minimum Marks

Find Maximum Salary

 MIN() & MAX() with GROUP BY

Department-wise Min & Max Salary

• One row per department

 With WHERE

•  Filters rows before aggregation.

 With Dates

•  Useful for first/last activity

 MIN() & MAX() with Strings

•  Based on alphabetical order.

 MIN() / MAX() with HAVING

•  Departments with high-paid employees

 Aggregate Functions & NULL Values

 Common Mistakes

•  Expecting MIN/MAX to include NULL
•  Using aggregate in WHERE
•  Forgetting GROUP BY
•  Confusing numeric vs string comparison

Interview Questions & MCQs (Very Important)

Q1. What does MIN() return?

A) Maximum value
B) Average value
C) Minimum value
D) Total value

Answer: C

Q2. What does MAX() return?

A) Minimum value
B) Maximum value
C) Count
D) Sum

Answer: B

Q3. Do MIN() and MAX() include NULL values?

A) Yes
B) No

Answer: B

Q4. Can MIN() and MAX() work with dates?

A) Yes
B) No

Answer: A

Q5. Which clause filters groups after aggregation?

A) WHERE
B) GROUP BY
C) HAVING
D) ORDER BY

Answer: C

Q6. Which is correct?

A) Correct
B) Incorrect

Answer: A

Real-Life Use Cases

•  Highest & lowest salary
•  First & last login date
•  Top & bottom scores
•  Sales range analysis
•  Performance reports

 Summary

• MIN() finds smallest value

• MAX() finds largest value

• Work with numbers, dates, strings

• Ignore NULL values

• Used with GROUP BY & HAVING

• Important for SQL exams & interviews