SQL - Introduction

SQL stands for Structured Query Language which is used for managing and manipulating relational databases. Developed in the 1970s, SQL allows users to create, read, update, and delete data (CRUD operations) efficiently. It is widely used in database systems like MySQL, PostgreSQL, Oracle, Microsoft SQL Server etc.

Key Features  of SQL

• Data Querying: SQL retrieves data using SELECT statements with filtering, sorting, and joining capabilities.
• Data Manipulation: Commands like INSERT, UPDATE, and DELETE modify database records.
• Data Definition: SQL defines database structures using CREATE, ALTER, and DROP for tables, indexes, and schemas.
• Data Control: It manages access permissions with GRANT and REVOKE for security.

Why SQL? 

• Retrieves and manipulates data stored in relational databases (RDBMS) like MySQL, Oracle, and SQL Server.
• Defines the structure and relationships of data within a database.
• Creates, modifies, and deletes database objects (tables, indexes).
• Inserts, updates, and deletes records using DML commands.
• Embeds into applications using modules, libraries (e.g., SQLAlchemy, JDBC), and pre-compilers.
• Creates and deletes databases and tables using CREATE DATABASE and DROP TABLE.
• Builds reusable database objects like views, stored procedures, and functions.
• Sets user permissions on tables, views, and procedures using GRANT and REVOKE.

SQL is essential for data analysts, developers, and database administrators, enabling efficient data handling in applications, business intelligence, and reporting. Learning SQL provides a strong foundation for working with databases in any domain.