Lab 04: Database & Persistence - Mashchenko Pavel

[PavMash]

Lab 04: Database & Persistence

Overview

Implemented database connection and CRUD operations for backend. Experimented with different kinds of local storage and database in frontend.

What was implemented:

Go backend component:

• Implemented database connection and migration
• Implemented CRUD operations for user managing with manual SQL approach

Flutter frontend component:

• Created class-inheritor of SharedPreferences and implemented CRUD methods for it
• Created class-inheritor of SharedPreferences and implemented CRUD methods for it
• Implemented local SQL database with CRUD and database managing operations

How to test:

Backend testing

1. cd labs/lab02/backend
2. go mod tidy
3. go test ./...

Frontend testing

1. cd labs/lab02/frontend
2. flutter pub get
3. flutter test
4. It is okay, if secure_storage_service tests do not pass.

Checklist:

• All tests pass
• Code passes linting
• Both Go and Flutter components work
• Follows course coding standards

[github-actions]

Lab 04 Test Results - Database & Persistence

🎯 Score: 5/6 (83.33333333333334%) - NECESSARY TASKS ONLY

🚀 Great progress! Almost mastered the core database operations!

📋 NECESSARY Task Completion:

Go Backend - NECESSARY Tasks

• ✅ 🔴 Data Models (User & Post)
• ✅ 🔴 Database Infrastructure
• ✅ 🔴 Manual SQL Repository

Flutter Frontend - NECESSARY Tasks

• ✅ 🔴 SharedPreferences Service
• ✅ 🔴 SQLite Database Service
• ❌ 🔴 Secure Storage Service

🔧 Component Details:

Backend (Go) - 3 NECESSARY Tasks:

• 🔴 Models: User & Post structs with validation and JSON serialization
• 🔴 Database: Connection management and goose migrations
• 🔴 Repository: Manual SQL CRUD operations using database/sql

Frontend (Flutter) - 3 NECESSARY Tasks:

• 🔴 SharedPreferences: Simple key-value storage for app settings
• 🔴 SQLite Service: Local database operations with sqflite package
• 🔴 Secure Storage: Encrypted storage for sensitive user data

🎯 OPTIONAL Learning Tasks:

After completing necessary tasks, explore these advanced patterns:

• 🟡 Scany Mapping: Automatic struct mapping with raw SQL
• 🟡 Squirrel Builder: Dynamic query building with fluent API
• 🟡 GORM ORM: Full object-relational mapping with associations

💡 Next Steps:

• Complete secure storage service for sensitive data

🛠️ Migration Commands

Use these Makefile commands for database management:

• make migrate-up - Run all migrations
• make migrate-down - Rollback last migration
• make migrate-status - Check migration status
• make setup-db - Fresh database setup

Explore different storage patterns and database approaches! 🚀