SQL Filtering: WHERE, IN, OR, AND, and More

Learn how to filter and refine data efficiently using SQL's filtering operators.

What is Filtering in SQL?

Filtering in SQL allows you to retrieve only the rows that meet certain conditions. The most common filtering clause is WHERE, which is used to limit the results based on specific criteria.

Using the WHERE Clause

The WHERE clause is used to filter records based on a specified condition.

-- Basic WHERE clause
SELECT * FROM employees
WHERE department = 'Sales';

Combining Conditions with AND and OR

The AND operator ensures that all conditions must be true, while OR allows any one of the conditions to be true.

-- Using AND and OR
SELECT * FROM employees
WHERE department = 'Sales' AND salary > 50000;

Filtering with IN

The IN operator is used to match multiple values without using multiple OR conditions.

-- Using IN for multiple values
SELECT * FROM employees
WHERE department IN ('Sales', 'Marketing', 'HR');

Using LIKE for Pattern Matching

The LIKE operator is useful for filtering text based on patterns.

-- Using LIKE for pattern matching
SELECT * FROM employees
WHERE name LIKE 'J%';

Using BETWEEN for Ranges

The BETWEEN operator allows filtering values within a range, inclusive of the boundary values.

-- Using BETWEEN for range filtering
SELECT * FROM employees
WHERE salary BETWEEN 40000 AND 60000;