How to Normalize Data to Third Normal Form 3NF

In this episode, I'm going to walk you through an example of normalizing your data. We'll start with a spreadsheet sample from a much larger spreadsheet, then work that original table through the design process of 1st, then 2nd, and 3rd Normal Forms. Each higher form creates efficiencies and integrity in your design, making it far more suitable for building an application on, designing an analytics warehouse for, or storing and using it on data science projects. This technique and skill is critical and incredibly valuable for database designers. 3NF is the level of normalization that you will see on the vast majority of databases in the business world, and it is important to understand the process of designing for it.

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[seanmackenziedataengineering]

After completing this video, I asked ChatGPT to: "please write an article of 1000 words on how to normalize data to 3NF" and here is what I got:

"Normalizing data to Third Normal Form (3NF) is a process of organizing a database to minimize redundancy and improve data integrity. The goal is to eliminate data anomalies and ensure data is stored in a structured and consistent manner. This article will provide a step-by-step guide on how to normalize data to 3NF.

1. Determine the functional dependencies
Before normalizing a database, it is important to identify the relationships between the data. A functional dependency is a relationship where one attribute determines another attribute. To determine the functional dependencies, you should consider the business rules and the relationships between the data.

2. Create the 1st Normal Form (1NF)
The first step in normalizing data to 3NF is to convert it to 1st Normal Form (1NF). To achieve this, you need to ensure that each attribute has a unique value, and the data is stored in separate tables. In 1NF, each row represents a single entity, and each column represents an attribute of that entity.

3. Create the 2nd Normal Form (2NF)
In the 2nd Normal Form, the data should be organized so that non-key attributes are dependent on the entire primary key. This means that each non-key attribute must depend on the entire primary key, and not just a part of it. To achieve this, you need to identify any partial dependencies and split the data into separate tables.

4. Create the 3rd Normal Form (3NF)
In 3NF, data is further organized to remove any transitive dependencies. A transitive dependency occurs when a non-key attribute depends on another non-key attribute. To eliminate transitive dependencies, you should create additional tables to store the dependent data.

5. Verify the Normalization
Once you have completed the normalization process, you should verify that the data is in 3NF by checking for redundancy, anomalies, and consistency. You can use tools like SQL scripts or data modeling software to verify the normalization.

In conclusion, normalizing data to 3NF is a crucial step in improving the quality and integrity of data. The process involves organizing data into separate tables, minimizing redundancy, and removing anomalies. By following these steps, you can ensure that your data is structured and consistent, and that it can be easily managed and queried.

Note: The process of normalizing data to 3NF is complex and requires a strong understanding of database design principles and techniques. If you are not familiar with these concepts, it is recommended to seek the assistance of a professional database administrator or consult specialized resources."

Pretty good article!

[mavronadir]

I'm brushing up on this topic as I'll be doing some DB modelling at work and I've got to say you have a great way to explain. Made me see things in a different and simpler way. Thank you!

[jonnytor]

Thank you very much, this helps so much when all hope is lost for my final exam. Thank you

[jg]

Thanks, this was very helpful as always

[steynkahrel]

Why would you put project_code and equip_id in a lookup tabel and not do the same for equip_id and depot_no? Are there any conventions about this?

[DANNYEL]

please how can i message you privately