What is Relational Database

• A relational database is a type of database management system (DBMS) that organizes and stores data in a structured manner, using a collection of tables with defined relationships between them.

• The concept of relational databases was introduced by Edgar F. Codd in the 1970s, and it has become the most widely used database model for managing and manipulating structured data.

• In a relational database, data is organized into tables, where each table consists of rows and columns. Each row represents a record or an individual data entry, while each column represents a specific attribute or field of the data. The columns are given names, and each row in the table has a unique identifier, known as a primary key, which distinguishes it from other rows.

• The key feature of a relational database is the ability to establish relationships between tables using common attributes. These relationships are defined by foreign keys, which are columns in one table that reference the primary key in another table. By establishing these relationships, data from different tables can be linked and retrieved together, allowing for efficient data retrieval and ensuring data integrity and consistency.

• The Structured Query Language (SQL) is the standard language used to interact with and manipulate relational databases. SQL provides a set of commands and operations to create, modify, and query data in the tables.

Advantages of relational databases include:

• Data integrity: The use of primary keys and foreign keys helps maintain data integrity and prevents inconsistencies or duplication in the database.

• Flexibility: The structure of a relational database allows for easy modification and expansion of data without altering the entire database.

• Query capabilities: SQL provides powerful query capabilities, enabling users to retrieve and analyze data with ease.

• Scalability: Relational databases can handle large amounts of data and can be scaled up to meet growing demands.

• Popular relational database management systems include MySQL, PostgreSQL, Oracle, Microsoft SQL Server, and SQLite, among others. These systems are widely used in various applications ranging from small-scale projects to large enterprise-level systems.