SQL Notes – SQL Fundamentals & Database CommandsFree

Complete SQL Notes covering the fundamentals of Structured Query Language (SQL), database operations, SQL DML and DDL commands, and commonly used SQL statements. The material explains SELECT, DISTINCT, WHERE, AND, OR, ORDER BY, INSERT INTO, UPDATE, DELETE, CREATE DATABASE, CREATE TABLE, constraints, and ALTER TABLE with syntax and practical examples.

The notes include examples using tables such as Persons and demonstrate how to retrieve specific columns, select all records, filter records using conditions, remove duplicate values, sort results in ascending or descending order, and combine multiple conditions.

It also covers INSERT INTO for adding records, UPDATE for modifying existing records, DELETE for removing records, and important warnings about using WHERE clauses. Database creation, table creation, NOT NULL, UNIQUE, PRIMARY KEY, CHECK, DEFAULT constraints, and modifying tables using ADD, DROP COLUMN, and ALTER COLUMN are also included.