Generate an Entity-Relationship Diagram in Compass

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 to Automatically infer relationships between collections. When enabled, Compass 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 Compass samples from your collections to generate your diagram. By default, Compass 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

Compass generates an entity-relationship diagram with the selected collections and displays it in the current tab. Compass also displays the Data Model Overview 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, Compass displays the existing diagrams in the Data Modeling tab.