Category: SQL Tutorial

SQL (Structured Query Language) is the standard language used to interact with relational databases. It allows you to store, retrieve, update, and manage data efficiently. SQL works with relational database systems such as: PostgreSQL...

Here is a clear, practical, and complete guide to SQL Data Types, covering all major database engines (MySQL, PostgreSQL, SQL Server, Oracle) with examples and best practices. ✅ What Are SQL Data Types? SQL...

📘 SQL SELECT Statement The SELECT statement is the most commonly used SQL command. It is used to retrieve data from one or more tables in a relational database. 1. Basic Syntax SELECT column1,...

Here is a clear, practical, and complete guide to SQL Hosting, explaining your options, how SQL databases are hosted, pricing considerations, cloud vs. on-premise, and best practices for production deployments. ✅ What Is SQL...

Here is a clear, safe, and practical guide to SQL Injection, including what it is, how it works, and how to prevent it in real-world systems. ⚠️ What Is SQL Injection? SQL Injection (SQLi)...

Here is a clear, practical, and complete guide to SQL Views, including syntax, behavior, updatable vs. non-updatable views, and examples for MySQL, PostgreSQL, SQL Server, and Oracle. ✅ What Is a SQL VIEW? A...

Here is a clear, practical, and complete guide to working with dates in SQL, including the most important functions and examples for MySQL, PostgreSQL, SQL Server, and Oracle. ✅ Date Types in SQL Most...

Here is a clear, practical, and complete guide to the SQL AUTO INCREMENT field, including syntax for MySQL, PostgreSQL, SQL Server, and Oracle. ✅ What Is an AUTO INCREMENT Field? An AUTO INCREMENT (or...

Here is a clear, practical, and complete guide to the SQL CREATE INDEX statement, including examples for MySQL, PostgreSQL, SQL Server, and Oracle, plus performance best practices. ✅ What an INDEX Does An index...

Here is a clear, practical, and complete guide to the SQL DEFAULT constraint, including syntax, behavior, examples, and DB-specific differences. ✅ What the DEFAULT Constraint Does A DEFAULT constraint automatically assigns a value to...