SQL Operators
Explained for Beginners

SQL queries become powerful when you stop just selecting data and start comparing, filtering, and combining conditions. That is exactly what SQL operators do.

If you are learning SQL for data analysis, operators are essential. Because real analysis is not just pulling data. It is filtering the right data.

This is where SQL starts becoming practical.

SQL operators are symbols or keywords used to perform operations on values. They help compare data, combine conditions, and calculate results.

SELECT *
FROM orders
WHERE revenue > 5000;

Here: > is an operator. It compares values. Meaning: “Return rows where revenue is greater than 5000.”

This is where beginner SQL becomes real-world SQL. Because analyst questions always involve conditions.

Examples:

Let’s break them down.

Arithmetic operators perform mathematical calculations.

Addition (+)

SELECT price + tax
FROM products;

Subtraction (-)

SELECT revenue - discount
FROM orders;

Useful for net revenue.

Multiplication (*)

SELECT quantity * unit_price
FROM order_items;

Useful for order value calculations.

Division (/)

SELECT revenue / customers
FROM metrics;

Use case: Average revenue per customer.

Comparison operators compare values. These are used constantly.

Logical operators combine multiple conditions. These are core analyst tools.

AND

All conditions must be true.

SELECT *
FROM customers
WHERE city = 'Mumbai'
AND is_premium = TRUE;

OR

At least one condition must be true.

SELECT *
FROM customers
WHERE city = 'Mumbai'
OR city = 'Delhi';

NOT

Reverses a condition. Cleaner equivalent: WHERE is_active = FALSE.

AND vs OR Example

-- Query 1:
WHERE city = 'Mumbai'
AND is_premium = TRUE
-- Returns Only: | Mumbai | TRUE |

-- Query 2:
WHERE city = 'Mumbai'
OR is_premium = TRUE
-- Returns: Multiple rows.

Set operators combine the results of multiple queries.

Interviews often test edge cases.

1. Which operator checks if two values are equal?
2. Which operator combines conditions where BOTH must be true?
3. Which operator combines query results and keeps duplicates?
4. Which operator finds the remainder of a division?

What Comes Next?

After operators, learn SQL aliases. Aliases help you name the calculated columns you just created using arithmetic operators.

Operators are the building blocks of business logic. Master them, and your SQL becomes incredibly powerful.