Database Management Systems (DBMS vs RDBMS) in SQL

Database Management Systems (DBMS) and Relational Database Management Systems (RDBMS) are software systems used to manage and organize data. While both serve the purpose of data management, there are significant differences in their features and functionality.

What is a DBMS?

A Database Management System (DBMS) is software that provides an interface to interact with databases. It allows users to store, retrieve, and manipulate data efficiently. However, it does not enforce relationships between data.

Key Features of DBMS:

• Stores data in files or non-relational formats.
• Does not support relationships between tables.
• Examples: Microsoft Access, FileMaker.

Example of DBMS Operations:

      -- Example of storing data in a DBMS-like system
      CREATE TABLE Employees (
          EmployeeID INT,
          Name VARCHAR(50),
          Department VARCHAR(50)
      );

      INSERT INTO Employees (EmployeeID, Name, Department)
      VALUES (1, 'John Doe', 'HR');
    

What is an RDBMS?

A Relational Database Management System (RDBMS) is an advanced type of DBMS that organizes data into tables and enforces relationships between them using keys. It follows the principles of the relational model proposed by Dr. E. F. Codd.

Key Features of RDBMS:

• Stores data in structured tables (relations).
• Supports relationships using primary and foreign keys.
• Ensures data integrity and consistency through constraints.
• Examples: MySQL, PostgreSQL, SQL Server, Oracle Database.

Example of RDBMS Operations:

      -- Create a table for Employees
      CREATE TABLE Employees (
          EmployeeID INT PRIMARY KEY,
          Name VARCHAR(50),
          DepartmentID INT
      );

      -- Create a table for Departments
      CREATE TABLE Departments (
          DepartmentID INT PRIMARY KEY,
          DepartmentName VARCHAR(50)
      );

      -- Insert data into Departments
      INSERT INTO Departments (DepartmentID, DepartmentName)
      VALUES (1, 'HR');

      -- Insert data into Employees
      INSERT INTO Employees (EmployeeID, Name, DepartmentID)
      VALUES (1, 'John Doe', 1);

      -- Retrieve data with relationships
      SELECT e.Name, d.DepartmentName
      FROM Employees e
      JOIN Departments d ON e.DepartmentID = d.DepartmentID;
    

Differences Between DBMS and RDBMS

Conclusion

While both DBMS and RDBMS are used to manage data, RDBMS offers additional features like relationships, constraints, and scalability, making it the preferred choice for modern applications. SQL is predominantly used with RDBMS to perform complex data operations efficiently.