Comparison operators
- SQL course
- Beginner
- Lesson 8/115
- 4 min
Learn =, <>, <, >, <=, >= operators.
Comparison operators
SQL has six basic comparison operators: =, <>, <, >, <=, >=. You compare columns with constants in conditions.
SELECT name FROM products
WHERE stock <= 5;This returns products with stock of 5 or fewer.
name is selected from products. WHERE keeps only the rows where stock <= 5 holds.
Comparison operators — details
There are two ways to write not-equal: <> and !=. Both are valid ANSI SQL; <> is more common. Text values go in single quotes, numbers without quotes.
For example, WHERE price >= 100 returns products costing 100 or more, and WHERE stock <> 0 returns those whose stock isn't zero.
Practice Comparison operators
Select name and stock from products where stock is less than 5.
Starter code
-- pick stock below 5
SELECT name, stock
FROM products
WHERESample solution
SELECT name, stock
FROM products
WHERE stock < 5Expected output
name stock Silgi 2 Cetvel 3
Questions and answers
Review the lesson questions together with their answers. To test yourself, solve the lesson interactively.
1 Less than or equal
SELECT name FROM products
WHERE stock ____ 5;SELECT name FROM products
WHERE stock <= 5;Explanation: <= means less than or equal; it returns products with stock of 5 or less.
2 What does <> mean?
- Equal to
- Less than
- Greater than
- Not equal to Correct answer
Explanation: <> means not equal.
3 Comparison operators: match the terms
| Term | Meaning |
|---|---|
= |
equal |
<> |
not equal |
<= |
less or equal |
>= |
greater or equal |