Chapter 4: Data Management

Welcome to Chapter 4: Data Management. In this part of Dyad Tutorial: Local-First AI App Building, you will build an intuitive mental model first, then move into concrete implementation details and practical production tradeoffs.

Data is the lifeblood of modern applications. In this chapter, we'll explore how to connect your Dyad applications to databases and manage data effectively.

Database Integration

Supported Databases

• SQLite (local development)
• PostgreSQL
• MySQL/MariaDB
• MongoDB
• Firebase/Firestore

Connection Setup

Connect to a PostgreSQL database with user authentication and session management

Data Models

Defining Schemas

Create structured data models:

Create user model with fields: id, email, name, created_at, preferences

Relationships

Establish data relationships:

Set up relationships between users, posts, and comments with foreign keys

CRUD Operations

Create Operations

Add functionality to create new records with form validation

Read Operations

Implement data fetching with filtering, sorting, and pagination

Update Operations

Build edit forms for updating existing records

Delete Operations

Add delete functionality with confirmation dialogs

Data Validation

Client-Side Validation

Add form validation for required fields, email formats, and data types

Server-Side Validation

Implement backend validation with error handling and user feedback

Advanced Features

Search and Filtering

Add search functionality and advanced filtering options

Data Export

Implement CSV/PDF export for reports and data backup

Real-Time Updates

Add real-time data synchronization across multiple users

Best Practices

Data Security

• Implement proper authentication
• Use parameterized queries
• Sanitize user inputs

Performance

• Implement caching strategies
• Use database indexes
• Optimize queries

Next Steps

You've learned data management fundamentals. Next, we'll explore API integration.

Ready for APIs? Continue to Chapter 5: API Integration

---

Generated by AI Codebase Knowledge Builder

Depth Expansion Playbook

How These Components Connect

flowchart TD
    A[Virtual filesystem layer] --> B{Operation}
    B -->|Write| C[Buffer change in memory]
    B -->|Read| D[Overlay on top of disk files]
    C --> E[User reviews diff]
    E -->|Accept| F[Flush to real filesystem]
    E -->|Reject| G[Discard virtual changes]
    D --> H[Consistent state for LLM context]