ERD Generation¶

Generate Entity-Relationship Diagrams from your Django models.

Basic Usage¶

python manage.py generate_erd -d mermaid

Options¶

Option	Description	Example
`-a APPS`	Filter by specific apps	`-a shopping,polls`
`-d DIALECT`	Output format	`-d mermaid`, `-d plantuml`, `-d dbdiagram`
`-o OUTPUT`	Output file path	`-o erd.md`

Output Formats¶

Mermaid.js¶

Best for: GitHub README files, documentation sites

python manage.py generate_erd -d mermaid -o erd.md

Output:

erDiagram
    Customer {
        varchar first_name
        varchar last_name
        varchar email
    }
    Order {
        ForeignKey customer
        datetime order_date
        decimal total
    }
    Customer ||--o{ Order : places

PlantUML¶

Best for: Detailed diagrams, enterprise documentation

python manage.py generate_erd -d plantuml -o erd.puml

Output:

@startuml
entity Customer {
    * id : bigint
    --
    varchar first_name
    varchar last_name
    varchar email
}
entity Order {
    * id : bigint
    --
    ForeignKey customer
    datetime order_date
    decimal total
}
Customer ||--o{ Order : places
@enduml

dbdiagram.io¶

Best for: Database design, quick prototyping

python manage.py generate_erd -d dbdiagram -o erd.txt

Output:

Table Customer {
  id bigint [pk]
  first_name varchar
  last_name varchar
  email varchar
}

Table Order {
  id bigint [pk]
  customer bigint [ref: > Customer.id]
  order_date datetime
  total decimal
}

Ref: Order.customer > Customer.id

App Filtering¶

Include only specific apps:

python manage.py generate_erd -a auth,shopping -d mermaid

Exclude apps by not listing them in the -a parameter.

Integration with Documentation¶

GitHub README¶

Generate ERD:

python manage.py generate_erd -d mermaid -o docs/erd.md

Add to README:

## Database Schema

```mermaid
```mermaid
# Paste content from erd.md

```

MkDocs Integration¶

Add to your docs folder and reference in mkdocs.yml:

nav:
  - Database Schema: erd.md

Tips¶

Use -d mermaid for GitHub-compatible diagrams
Use -d plantuml for complex schemas
Use -d dbdiagram for database design collaboration
Save output to files for version control
Regenerate ERDs after model changes