Database Diagrams: Your Guide to Database Design & Structure

Organizations across all industries, from online shopping platforms to schools and libraries and many more, use databases. This is because they’re all tracking and storing large amounts of information that help their operations run more smoothly.

With that in mind, it’s important to get databases right. You want an efficient, functional database that helps you find all the information you need when you need it. In this blog, we’ll guide you through the steps to diagram your way to a successful database.

What Are Database Diagrams?

A database diagram is a visual representation of the structure of a database. Database diagrams can be used either as a tool for database planning and development or a documentation piece for a database that already exists.

The most common method of drawing a database diagram is an entity-relationship diagram, although database structures are sometimes also represented by UML diagrams. 

Types of Database Diagrams

There are three types of database diagrams that illustrate the database at varying levels of detail. Conceptual database diagrams provide only a broad overview of the database’s entities and primary relationships and are the least detailed and technical type of database diagram, ideal for communicating project information to non-technical stakeholders.

Logical database diagrams are a little more detailed than a conceptual diagram, but they still don’t need to include details related to specific database management systems. These are best for the initial planning phase. 

Logical diagrams also provide an outline for the final type of database diagram, physical database diagrams, which are the most detailed, applying the constraints and conventions of a specific database management system. 

Why Are Database Diagrams Important?

Database diagrams are a valuable resource for both planning and maintenance of a database. As you plan out the structure of a new database, a database diagram will help you identify inefficiencies and optimize the way your data is structured so you can avoid roadblocks and errors further along in the process.

Once the database is implemented, database diagrams are helpful for understanding the logic behind the database at a glance. They also make further development and expansion of the database faster and easier. 

How to Draw a Database Diagram

Drawing a database diagram is easy with a tool like Gliffy that allows you to diagram directly in Confluence alongside your technical documentation.

For a more specific guide to individual database diagram types, you’ll want to check out our specific tutorials for entity-relationship diagramming or UML diagramming.

If you’re looking for a more general introduction to database diagramming and the approach you’ll need to take to design a successful database, read on and start your free evaluation of Gliffy to follow along with these steps!

Research Requirements

If you’re diagramming a database that already exists, you can skip this step — it’s safe to assume that the requirements for this database were defined and applied before it was built.

However, the most common time to create a database diagram is during the process of planning its design. In this case, the first step both for planning your database and creating your database diagram is to understand its purpose and identify its requirements.

For example, who will be using your database? If multiple people or groups will need to access it for different purposes, how can you effectively meet those varying needs? What existing data do you already have? What will you need to gather? Answering these questions will form the foundation of your database’s structure.

Group Information

This step is where you’ll start to create your diagram. Using the requirements information that you determined in the previous step, create categories that break down information into the smallest possible pieces.

These categories might be data points such as order numbers or phone numbers, but the specific data included in your database will vary depending on the type of information your organization needs to collect.

During the database development process, you’ll group related data into tables with rows representing records and columns representing a certain type of data, but all you will need for your database diagram is a title for each table and a list of the attributes that it contains. These will be listed together in a single box — an “entity” in your entity-relationship diagram. 

Visualize Relationships

Once your entities are defined, you’ll need to visualize the relationships between them with lines of cardinality. These define the quantity of elements that interact between two particular tables.

Examples of relationship types in a database include one-to-one, represented by a line with a dash on each end; one-to-many, indicated with crow’s foot notation; and many-to-many, represented by a double crow’s foot line.

One-to-many relationships are the most common type in a database diagram — often, if you’re seeing a one-to-one or many-to-many relationship as you start to visualize your database, that’s a sign to take another look at the way your data is organized and further optimize its structure.

Normalize Your Data

Congratulations! At this point, you have a solid working database diagram. However, before you start building out your database in a database management system, there’s one last thing you’ll need to do: make sure your database structure adheres to industry standards for data normalization. This will help you ensure that your database won’t have errors or inefficiencies.

Draw a Database Diagram in Confluence

With Gliffy for Confluence, you can visualize your database structure alongside other project documentation directly in Confluence for more efficient communication and collaboration.

Gliffy also allows you to view and manage version history as you make updates to your diagram, and whenever you make an update, that update is automatically reflected in all copies of your diagram across your entire Confluence space.

Ready to get started? Visit our entity-relationship diagram tutorial for more help with database diagramming, or get started with your 30-day free evaluation of Gliffy and diagram your way to effective database design and management.

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