🔽 SQL MIN() Function – How to Find the Smallest Value in a Column

The SQL MIN() function is one of the most used aggregate functions in SQL. It helps you retrieve the minimum (smallest) value in a specific column, whether it’s numeric, text, or date-based.

In this tutorial, you’ll learn:

✅ What the MIN() function does
🔧 Syntax and usage
📊 Real-life examples
⚠️ Tips to avoid common mistakes

✅ What is SQL MIN()?

The MIN() function returns the smallest value from a group of rows in a column. It’s perfect for identifying the lowest price, earliest date, or alphabetically first text.

🔧 Syntax

SELECT MIN(column_name)
FROM table_name
WHERE condition;

column_name: The column you want to find the minimum value in.
table_name: The table containing the data.
WHERE: Optional condition to filter records.

📊 SQL MIN() Function Examples

🧪 Example 1: Find the Lowest Salary

SELECT MIN(salary) AS lowest_salary
FROM employees;

💰 This returns the minimum salary in the employees table.

🧪 Example 2: Get the Earliest Hire Date

SELECT MIN(hire_date) AS first_hired
FROM employees;

📅 Use this to find when the first employee joined.

🧪 Example 3: Find Minimum Score per Student

SELECT student_id, MIN(score) AS lowest_score
FROM test_results
GROUP BY student_id;

📉 Useful in analytics to find the worst performance per student.

🧪 Example 4: Alphabetically First Name

SELECT MIN(last_name) AS first_name
FROM customers;

🔤 Returns the name that comes first alphabetically.

🧠 MIN() with GROUP BY

Use GROUP BY to apply MIN() to each group in your dataset:

SELECT department_id, MIN(salary) AS min_salary
FROM employees
GROUP BY department_id;

This returns the lowest salary in each department.

🧠 Pro Tip: Use MIN() in Subqueries

SELECT *
FROM employees
WHERE salary = (
    SELECT MIN(salary)
    FROM employees
);

✔️ This retrieves all employees earning the minimum salary.

⚠️ Common SQL MIN() Mistakes

❌ Mistake	✅ Fix
Using `MIN()` with multiple columns without `GROUP BY`	Use `GROUP BY` with all non-aggregated columns
Expecting multiple values	`MIN()` returns a single value per group
Including NULLs	`MIN()` automatically ignores NULLs

🔍 SQL MIN() Function Use Cases

🏢 HR: Find the lowest salary
🛒 Retail: Get the cheapest product
📅 Events: Identify the earliest transaction
📝 Exams: Report lowest marks per student

🏁 Summary

Feature	Description
Function	`MIN()`
Returns	The smallest value
Works with	Numbers, text, dates
Ignores NULLs	✅ Yes
Use with GROUP BY	✅ Yes

MIN Function