Generate an Entity-Relationship Diagram in Atlas

In Atlas, go to the Data Explorer page for your project.

1. If it's not already displayed, select the organization that contains your project from the Organizations menu in the navigation bar.

2. If it's not already displayed, select your project from the Projects menu in the navigation bar.

3. In the sidebar, click Data Explorer under the Database heading.

   The Data Explorer displays.

Open the Data Modeling tab

In the left sidebar, click Data Modeling.

Click Generate diagram.

If you have existing diagrams saved in the Data Modeling tab, you can create a new diagram by clicking Generate new diagram in the upper-right corner of the screen.

Set up your new diagram.

In the New diagram setup modal:

• Select which MongoDB connection to use to generate your diagram.

• Select which database to use for your data model diagram.

• Input a name for your diagram.

After you specify each field, click Next.

Select collections.

Use the checkboxes to select which collections to include in your data model diagram. You can also use the search bar to filter for specific collections.

After you select your collections, click Next.

(Optional) Toggle automatically inferred relationships.

In the Diagram Settings modal, you can choose whether you want Atlas to Automatically infer relationships between collections. When enabled, Atlas analyzes the selected collections and adds relationships based on indexed fields that contain references to other collections.

You can also manually add and edit relationships after you generate your diagram.

(Optional) Configure document sampling.

In the Diagram Settings modal, you can specify how many documents Atlas samples from your collections to generate your diagram. By default, Atlas samples 100 documents per collection.

Larger sample sizes improve accuracy but may increase analysis time and memory usage. Smaller sample sizes decrease analysis time and memory usage but may miss infrequent fields or relationships.

You can also select whether you want to generate a diagram that samples all documents in your collections. Consider the size of your dataset and available resources on your device before you select All documents.

Click Generate.

Atlas generates an entity-relationship diagram with the selected collections and displays it in the current tab. Atlas also displays the side panel where you can rename your diagram and view the following information:

• The database you used to generate your diagram

• When you first generated the diagram

• When you last updated your diagram

After you generate a diagram, Atlas displays the existing diagrams in the Data Modeling tab.