What is the WHERE clause?

The WHERE clause is used to filter rows in a SQL query.

It helps you return only the rows that match a condition instead of returning every row from the table.

How WHERE works

A basic WHERE query follows this pattern.

SELECT
    column_name
FROM table_name
WHERE condition;

For example, this query returns only employees from the Sales department.

SELECT
    employee_name,
    department,
    salary
FROM Employees
WHERE department = 'Sales';

Sample table

We will use this Employees table to understand how WHERE filters rows.

Filtering by department

Text values in SQL are usually written inside single quotes.

This query returns only rows where the department is Sales.

SELECT
    employee_name,
    department,
    salary
FROM Employees
WHERE department = 'Sales';

Filtering with comparison operators

You can also use WHERE with comparison operators such as >, <, >=, <=, and =.

This query returns employees with a salary greater than 40000.

SELECT
    employee_name,
    department,
    salary
FROM Employees
WHERE salary > 40000;

Key takeaway