### Author: Agnieszka Kozubek

Agnieszka is a Chief Content Officer at Vertabelo. Before coming to Vertabelo, she worked as a Java programmer. She has a PhD in mathematics and over 10 years of experience in teaching mathematics and computer science at the University of Warsaw. In her free time, she enjoys reading a good book, going mountain hiking and practicing yoga.

### How to Normalize a Database Into 2NF and 3NF (With Examples)

We present a practical example of how to normalize a table that is in the first normal form (1NF) into a set of tables in the third normal form (3NF). Database normalization is a very important concept in database design. Every database designer should know the rules for different normal forms. In practice, the most important normal form is the third normal form (3NF). If you want to be a database designer, you should know how to check if a table is in 3NF.

### What Is a Candidate Key in Database Design?

A candidate key is an important concept in database normalization. Read on to find out what a candidate key is and how to check if a set of attributes is a candidate key. The candidate key, also simply called a key, is an important part of database design. It is the theoretical foundation for technical concepts like primary and alternate (unique) keys. Every database designer should be aware of how to identify candidate keys and how to choose the right one for their table.

### How To Find the Closure of a Set of Attributes (With Examples)

Do you know what a closure of a set of attributes is? Do you know how to find it? This knowledge is essential for database normalization. In this article, learn what a closure of a set of attributes is and how to find it with real-world examples. Finding the closure of a set of attributes is an important topic for relational databases. The closure of a set of attributes is taught in every university database class.

### What Is a One-to-One Relationship in a Database?

What is a one-to-one relationship in data modeling? How do you implement this relationship in a database? The examples in this article will answer these questions. There are three types of relationships between entities (tables) in data modeling: One-to-many relationships (also denoted as 1:M). Many-to-many relationships (M:N). One-to-one relationships (1:1). The most common type of relationship is a one-to-many relationship, where a record in one entity can be referenced by multiple records in another entity.

### How To Remember the Rules for Database Normal Forms

Database Normalization in Simple English Have you heard of 2NF, 3NF, and BCNF? Do you know what the database normal forms mean? In this article, you will learn database normalization in simple English. With real-world examples, you will better understand what normal forms are, why there are different types, and why we need them. Database courses typically teach database normalization and normal forms abstractly. Functional dependencies and normalization problems are defined using letters (e.

### Normalization in Relational Databases: First Normal Form (1NF), Second Normal Form (2NF), and Third Normal Form (3NF)

What is database normalization? What are the different normal forms, and what do they do? Find out in this article. Normalization in relational databases is a design process that minimizes data redundancy and avoids update anomalies. Basically, you want each piece of information to be stored exactly once; if the information changes, you only have to update it in one place. The theory of normal forms gives rigorous meaning to these informal concepts.

### How to Store Authentication Data in a Database. Part 1

How difficult is it to program a user login function for an application? Novice developers think it’s very easy. Experienced developers know better: it is the most sensitive process in your application. Errors in login screens can lead to serious security issues. In this article we take a look at how to store authentication data in your database. The most common way to authenticate users nowadays is with user name and password.

### 5 Must-Read Database Modeling Books?

I recently realized that our database modeling library could use a few more advanced titles. So I headed over to Amazon to see what they had on offer. There are plenty of introductory books for beginners that tell you how to normalize data, and introduce you to indexes, but what about something for the professional, grown-up database modeler? Here are 5 of the best database modeling books I found (listed in no particular order) that go beyond the basics and come highly recommended by Amazon reviewers.