Class Diagrams

What are Class Diagrams?

Mermaid's class diagrams help you visualize data structures and their relationships in your projects. For analytics engineers, they're particularly useful for documenting data models, transformation logic, and system architectures.

Creating Your First Class Diagram

1. Launch DinoAI: From Code IDE, access DinoAI to start creating diagrams.

2. Use a Simple Prompt: Tell DinoAI what kind of Class Diagram you want to create. For example:

- "Create a mermaid class diagram showing my data model classes with attributes and methods"

- "Generate a mermaid class diagram for my dbt™ transformation logic with class relationships"

- "Build a mermaid class diagram showing my data pipeline components and their interactions"

1. Get Your Diagram: DinoAI will generate a complete .mmd file with proper Mermaid syntax.

2. Preview Your Work: Click the eye icon (👁️) to preview your diagram in real-time as you edit.

3. Iterate and Refine: Modify the generated .mmd file directly, or ask DinoAI to make specific changes.

Example:

---
title: Animal example
---
classDiagram
    note "From Duck till Zebra"
    Animal <|-- Duck
    note for Duck "can fly\ncan swim\ncan dive\ncan help in debugging"
    Animal <|-- Fish
    Animal <|-- Zebra
    Animal : +int age
    Animal : +String gender
    Animal: +isMammal()
    Animal: +mate()
    class Duck{
        +String beakColor
        +swim()
        +quack()
    }
    class Fish{
        -int sizeInFeet
        -canEat()
    }
    class Zebra{
        +bool is_wild
        +run()
    }

Reusable Class Diagrams prompts for you and your team

You can create custom, standardized .dinoprompts for Mermaid's Class Diagrams that ensure consistency across your data team. See step-by-step guide.

---

Diagram Syntax Guide

Class Structure

A class diagram represents data objects and their relationships. Each class shows:

• The class name

• Its attributes (properties)

• Its methods (operations)

Basic Syntax

classDiagram
    class DataModel {
        +tableName: string
        +schema: string
        +refreshData()
        -validateSchema()
    }

Access Levels

Show visibility with these symbols:

• + : Public access

• - : Private access

• # : Protected access

• ~ : Internal access

Connections

Show relationships between classes:

classDiagram
    FactTable --> DimensionTable
    BaseModel <|-- CustomModel

Common relationships:

• Parent-child: <|--

• Contains: *--

• Uses: -->

• Optional: o--

Data Team Examples

Data Models

classDiagram
    class FactSales {
        +order_date: date
        +customer_key: int
        +product_key: int
        +calculateRevenue()
    }
    class DimCustomer {
        +customer_key: int
        +customer_name: string
        +getLTV()
    }
    FactSales --> DimCustomer

Transformation Pipeline

classDiagram
    class Staging {
        +raw_data: table
        +clean()
        +validate()
    }
    class Warehouse {
        +processed_data: table
        +transform()
        +loadData()
    }
    Staging --> Warehouse

Best Practices

1. Name classes clearly and consistently

2. Show only relevant attributes and methods

3. Group related classes together

4. Add notes for complex relationships

5. Keep diagrams focused on one aspect of your system

Additional Resources

For more syntax options and advanced features, visit the official Mermaid documentation