Beginners - Simplify Database

NULL in SQL Explained Simply: IS NULL, COALESCE and Common Traps

Understand what NULL means in SQL, why = NULL never works, and how to handle missing values with IS NULL, COALESCE and NULLIF.

Learn how SQL constraints like NOT NULL, UNIQUE, CHECK and DEFAULT protect your data, with simple examples you can use right away.

A practical guide to SQL data types: numbers, text, dates and more, with differences between SQL Server, MySQL and PostgreSQL.

Learn how to add, change and remove data in SQL with INSERT, UPDATE and DELETE, plus the safety habits that stop costly mistakes.

My pick of the best SQL and database books for every level, from your first query to database design, performance and large-scale data systems.

What primary keys and foreign keys are, how they differ, and why they keep your database consistent, explained with simple examples.

Learn how to filter, sort and limit query results in SQL with WHERE, ORDER BY and LIMIT, using simple real-world examples.

“Big data” is one of those tech buzzwords you hear everywhere — in news articles, job listings, business meetings, and

When people talk about databases in corporate environments, one name comes up more than any other: Microsoft SQL Server. It

If MySQL is the most popular database on the web, PostgreSQL is the one developers love most. Year after year,