Stored Procedures and Functions in DBMS - Comprehensive Guide

Stored procedures and functions are essential components in Database Management Systems (DBMS) that encapsulate sets of SQL statements for execution. They improve code reusability, modularity, and security.

Why Stored Procedures and Functions?

Stored procedures and functions offer advantages such as code organization, reduced redundancy, and improved security in database operations.

Differences Between Stored Procedures and Functions:

While both stored procedures and functions encapsulate SQL code, functions typically return values, while procedures don't necessarily return values.

Creating and Using Stored Procedures:

Here's how you can create and use a stored procedure:

Step 1: Write SQL Code

Define the SQL statements you want to include in the procedure.

Step 2: Create the Procedure

Use the CREATE PROCEDURE statement to create the procedure:


            CREATE PROCEDURE GetEmployeeCount (OUT employeeCount INT)
            BEGIN
                SELECT COUNT(*) INTO employeeCount FROM Employees;
            END;

Calling Stored Procedures:

Call the stored procedure using the CALL statement:


            CALL GetEmployeeCount(@count);

Creating and Using Functions:

Here's how you can create and use a function:

Step 1: Write SQL Code

Define the SQL statements you want the function to execute.

Step 2: Create the Function

Use the CREATE FUNCTION statement to create the function:


            CREATE FUNCTION CalculateTotalSales(orderID INT) RETURNS DECIMAL(10, 2)
            BEGIN
                DECLARE total DECIMAL(10, 2);
                SELECT SUM(Amount) INTO