SQL Interview Summary Notes [Structured Query Language]

SQL Complete Mastery
Guide
Professional Reference with Perfect Visual
Hierarchy

, 📋 Learning Journey Overview

• 🎯 SQL Foundations & Architecture
– • Command categories and basic concepts




• 🔧 DDL (Data Definition Language)
– • CREATE, ALTER, DROP, TRUNCATE operations




• 🔄 DML (Data Manipulation Language)
– • INSERT, UPDATE, DELETE operations




• 🔍 Advanced Query Mastery
– • SELECT operations and data retrieval

, 🎯 Understanding SQL

• What is SQL?
– • SQL = Structured Query Language
– • Industry standard for relational databases
– • Universal language for data operations




• 📊 Command Architecture:




• DDL (Data Definition Language):
– • Controls table and database structure
– • Manages schema and object definitions




• DML (Data Manipulation Language):
– • Handles data modification operations

, 🔧 CREATE Operations

• 🏗️
Table Creation:




• CREATE TABLE table_name (
• column1 VARCHAR(100),
• column2 INT
• );




• Real Example:




• CREATE TABLE employees (
• emp_id INT PRIMARY KEY,
• name VARCHAR(100) NOT NULL
• );