First normal form facts for kids

First normal form (often called 1NF) is an important rule for how we organize information in databases. Imagine a database as a super organized digital filing cabinet. Inside, information is stored in tables, which look a lot like spreadsheets.

When a table is in First Normal Form, it means it follows some basic rules to keep data neat and easy to use. It's the first step in making sure your database is well-structured and efficient.

What is First Normal Form (1NF)?

First Normal Form (1NF) is the most basic rule for organizing data in a database table. Think of it as making sure each piece of information has its own clear spot. If a table follows 1NF, it means:

• Every cell in the table holds only one single piece of information.
• There are no repeating groups of columns.

Let's look at an example to understand this better.

Atomic Values: One Fact Per Cell

The first rule of 1NF is that every "cell" in your table should contain only one value. This is called an "atomic value." Imagine a cell in a spreadsheet. It should not contain a list of things, only one specific item.

Bad Example: Multiple Values in One Cell

Let's say you have a table for a game store's inventory.

In this example, the "Genres" column has multiple values (like "Sci-Fi, Action, RPG") in a single cell. This breaks the 1NF rule. It makes it hard to search for all games that are "Action" or to sort by genre.

Good Example: Atomic Values

To fix this, you would make sure each cell has only one piece of information. For genres, you might need a separate table or a different way to link genres. For players, you could list the minimum and maximum players in separate columns.

Even better, you could have a separate table for genres and link them, but for 1NF, the main point is that each cell has a single value.

No Repeating Groups of Columns

The second rule of 1NF is that you should not have columns that repeat the same type of information within the same table.

Bad Example: Repeating Columns

Imagine a table for a student's courses:

Here, "Course 1, Grade 1," "Course 2, Grade 2," etc., are repeating groups. What if a student takes more than 3 courses? You'd have to add more columns, which is messy and inefficient.

Good Example: No Repeating Columns

To fix this, you would create a new row for each course a student takes. This means the student's ID would appear multiple times, but each row would represent one specific course enrollment.

This way, you can add as many courses as needed without changing the table's structure. It's much more flexible and organized.

Why is 1NF Important?

First Normal Form is the very first step in database normalization. Normalization is a process of organizing the columns and tables of a relational database to reduce data redundancy and improve data integrity.

• Easier Data Management: When data is organized according to 1NF, it's much easier to add, update, or delete information without causing problems.
• Better Searches: You can search for specific information more accurately. For example, finding all games with the "Action" genre becomes simple.
• Less Redundancy: It helps avoid storing the same information multiple times, which saves space and reduces the chance of errors.
• Foundation for More Rules: 1NF is the basic foundation. Once a table is in 1NF, it can then be improved further by applying other normalization rules (like Second Normal Form, 2NF, and Third Normal Form, 3NF).

Think of 1NF as cleaning up your room before you start organizing your closet. You need to make sure everything is off the floor and in its basic place before you can arrange it perfectly.

See also

In Spanish: Primera forma normal para niños