Introduction to Conditional Functions in MySQL

Conditional functions in MySQL, including IF and CASE, allow you to perform conditional logic within your SQL queries. These functions are valuable for making decisions and manipulating data based on specified conditions. In this guide, we'll explore how to use IF and CASE functions effectively.

The IF Function

The IF function is used to perform conditional checks and return different values based on the result. Its basic syntax is as follows:

IF(condition, value_if_true, value_if_false)

The IF function evaluates the condition, and if it's true, it returns "value_if_true"; otherwise, it returns "value_if_false."

The CASE Function

The CASE function allows you to perform more complex conditional logic with multiple conditions. It has both simple and searched case forms. The basic syntax for the simple form is as follows:

CASE expression
    WHEN value1 THEN result1
    WHEN value2 THEN result2
    ...
    ELSE default_result
END

The searched form of CASE can be used for more complex conditions and is written as:

CASE
    WHEN condition1 THEN result1
    WHEN condition2 THEN result2
    ...
    ELSE default_result
END

Examples of Using Conditional Functions

Let's consider some examples to understand how to use conditional functions in MySQL:

SELECT product_name, IF(price > 100, 'Expensive', 'Affordable') AS price_category
FROM products;

SELECT employee_name,
    CASE
WHEN salary > 50000 THEN 'High'
WHEN salary > 30000 THEN 'Medium'
ELSE 'Low'
    END AS salary_category
FROM employees;

Conclusion

Conditional functions like IF and CASE are powerful tools in MySQL, allowing you to make decisions and manipulate data based on specified conditions. Understanding how to use these functions effectively can enhance the flexibility and logic of your SQL queries.