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Index

1. Introduction to SQL
   • What is SQL?
   • History and Evolution
   • Importance of SQL in Databases
   • Types of SQL Commands
     • DDL (Data Definition Language)
     • DML (Data Manipulation Language)
     • DCL (Data Control Language)
     • TCL (Transaction Control Language)
2. Basic SQL Commands
   • Creating a Database and Tables
     • CREATE DATABASE
     • CREATE TABLE
     • Data Types
   • Basic Data Manipulation
     • INSERT INTO
     • SELECT
     • UPDATE
     • DELETE
3. SQL Functions and Operators
   • String Functions
     • CONCAT
     • SUBSTRING
     • LENGTH
   • Numeric Functions
     • ABS
     • ROUND
     • FLOOR
   • Date Functions
     • CURRENT_DATE
     • DATEADD
     • DATEDIFF
   • Operators
     • Arithmetic Operators
     • Comparison Operators
     • Logical Operators
4. SQL Clauses
   • WHERE Clause
     • Filtering Data
   • ORDER BY Clause
     • Sorting Data
   • GROUP BY Clause
     • Aggregating Data
   • HAVING Clause
     • Filtering Aggregated Data
5. Joins and Subqueries
   • Types of Joins
     • INNER JOIN
     • LEFT JOIN
     • RIGHT JOIN
     • FULL JOIN
     • CROSS JOIN
   • Subqueries
     • Single-Row Subqueries
     • Multi-Row Subqueries
     • Correlated Subqueries
6. Advanced SQL Concepts
   • Views
     • Creating and Managing Views
   • Indexes
     • Types and Uses of Indexes
     • Creating and Dropping Indexes
   • Stored Procedures
     • Creating and Executing Stored Procedures
   • Triggers
     • Creating and Managing Triggers
   • Transactions
     • ACID Properties
     • COMMIT, ROLLBACK, and SAVEPOINT
7. Performance Tuning and Optimization
   • Query Optimization
     • Understanding Execution Plans
     • Index Optimization
   • Database Normalization
     • Normal Forms (1NF, 2NF, 3NF, BCNF)
   • Common Performance Issues
     • Identifying and Resolving Bottlenecks
8. SQL Security
   • User Management
     • Creating and Managing Users
   • Roles and Permissions
     • Granting and Revoking Privileges

Introduction to SQL

What is SQL?

SQL, or Structured Query Language, is the standard language used to interact with relational databases. It's the tool we use to communicate with a database, to perform tasks such as retrieving data, updating records, and creating tables. Think of SQL as a way to ask your database a question or give it an instruction. Whether you want to find a list of customers, add a new order, or update a product's price, SQL is the language that makes it happen.

History and Evolution

SQL was born out of the need for a standard method of managing and manipulating relational databases. It all started in the early 1970s at IBM, where Donald D. Chamberlin and Raymond F. Boyce developed SEQUEL (Structured English Query Language) to interact with the company's System R, one of the first relational database systems. SEQUEL was later renamed SQL due to trademark issues.

By the late 1970s, SQL had gained traction and was adopted by several database vendors. In 1986, the American National Standards Institute (ANSI) standardized SQL, solidifying its role in the world of databases. Over the years, SQL has evolved, adding new features and capabilities with each update. Major databases like Oracle, MySQL, SQL Server, and PostgreSQL have their own versions and extensions of SQL, but the core language remains the same.