add changes
This commit is contained in:
AD2025
260
MIGRATION_SUMMARY.md
Normal file
260
MIGRATION_SUMMARY.md
Normal file
@@ -0,0 +1,260 @@
|
||||
# MongoDB to MySQL Migration Summary
|
||||
|
||||
## Overview
|
||||
This document has been successfully migrated from **MongoDB/Mongoose** to **MySQL/Sequelize** architecture.
|
||||
|
||||
---
|
||||
|
||||
## Major Changes
|
||||
|
||||
### 1. **Technology Stack Update**
|
||||
- **Changed from**: MongoDB with Mongoose ODM
|
||||
- **Changed to**: MySQL 8.0+ with Sequelize ORM
|
||||
- **Stack name**: Updated from "MEAN Stack" to "MySQL + Express + Angular + Node"
|
||||
|
||||
### 2. **Database Schema Transformation**
|
||||
|
||||
#### ID Strategy
|
||||
- **MongoDB**: ObjectId (12-byte identifier)
|
||||
- **MySQL**: UUID (CHAR(36) or BINARY(16))
|
||||
|
||||
#### Data Types Mapping
|
||||
| MongoDB | MySQL |
|
||||
|---------|-------|
|
||||
| ObjectId | CHAR(36) UUID |
|
||||
| String | VARCHAR/TEXT |
|
||||
| Number | INT/DECIMAL |
|
||||
| Boolean | BOOLEAN |
|
||||
| Date | TIMESTAMP |
|
||||
| Mixed | JSON |
|
||||
| Array | JSON or Junction Tables |
|
||||
| Embedded Documents | JSON or Separate Tables |
|
||||
|
||||
#### Schema Design Approach
|
||||
- **Normalized tables** for core entities (users, questions, categories)
|
||||
- **Junction tables** for many-to-many relationships (bookmarks, achievements, quiz questions)
|
||||
- **JSON columns** for flexible data (question options, keywords, tags, feature restrictions)
|
||||
- **Proper foreign keys** with cascading deletes/updates
|
||||
|
||||
### 3. **Database Tables Created**
|
||||
|
||||
1. **users** - User accounts and statistics
|
||||
2. **categories** - Question categories
|
||||
3. **questions** - Question bank with guest visibility controls
|
||||
4. **quiz_sessions** - Active and completed quiz sessions
|
||||
5. **quiz_session_questions** - Junction table for session questions
|
||||
6. **quiz_answers** - Individual question answers
|
||||
7. **guest_sessions** - Guest user sessions
|
||||
8. **guest_settings** - Guest access configuration
|
||||
9. **guest_settings_categories** - Junction table for guest-accessible categories
|
||||
10. **achievements** - Achievement definitions
|
||||
11. **user_achievements** - User earned achievements
|
||||
12. **user_bookmarks** - User bookmarked questions
|
||||
|
||||
### 4. **Key Features**
|
||||
|
||||
#### Indexes Added
|
||||
- Primary key indexes (UUID)
|
||||
- Foreign key indexes for relationships
|
||||
- Composite indexes for common queries
|
||||
- Full-text search indexes on question content
|
||||
- Performance indexes on frequently queried columns
|
||||
|
||||
#### MySQL-Specific Optimizations
|
||||
- InnoDB storage engine
|
||||
- UTF8MB4 character set for emoji support
|
||||
- Connection pooling configuration
|
||||
- Query optimization examples
|
||||
- Backup and restore strategies
|
||||
|
||||
### 5. **Sequelize Models**
|
||||
|
||||
All models include:
|
||||
- UUID primary keys
|
||||
- Proper associations (hasMany, belongsTo, belongsToMany)
|
||||
- Field name mapping (camelCase to snake_case)
|
||||
- Timestamps (created_at, updated_at)
|
||||
- Validation rules
|
||||
- Indexes defined at model level
|
||||
|
||||
### 6. **Configuration Updates**
|
||||
|
||||
#### Environment Variables
|
||||
```bash
|
||||
# Old (MongoDB)
|
||||
MONGODB_URI=mongodb://localhost:27017/interview_quiz
|
||||
|
||||
# New (MySQL)
|
||||
DB_HOST=localhost
|
||||
DB_PORT=3306
|
||||
DB_NAME=interview_quiz_db
|
||||
DB_USER=root
|
||||
DB_PASSWORD=your_password
|
||||
DB_DIALECT=mysql
|
||||
```
|
||||
|
||||
#### Dependencies to Update
|
||||
```bash
|
||||
# Remove
|
||||
npm uninstall mongoose
|
||||
|
||||
# Install
|
||||
npm install sequelize mysql2
|
||||
npm install -g sequelize-cli
|
||||
```
|
||||
|
||||
### 7. **Migration Strategy**
|
||||
|
||||
#### Development Setup
|
||||
1. Install MySQL 8.0+
|
||||
2. Create database with UTF8MB4
|
||||
3. Run Sequelize migrations
|
||||
4. Seed initial data
|
||||
5. Start application
|
||||
|
||||
#### Migration Commands
|
||||
```bash
|
||||
# Initialize Sequelize
|
||||
npx sequelize-cli init
|
||||
|
||||
# Create migration
|
||||
npx sequelize-cli migration:generate --name migration-name
|
||||
|
||||
# Run migrations
|
||||
npx sequelize-cli db:migrate
|
||||
|
||||
# Rollback migration
|
||||
npx sequelize-cli db:migrate:undo
|
||||
|
||||
# Seed database
|
||||
npx sequelize-cli db:seed:all
|
||||
```
|
||||
|
||||
### 8. **Security Enhancements**
|
||||
|
||||
- **SQL Injection Prevention**: Sequelize parameterized queries
|
||||
- **Prepared Statements**: All queries use prepared statements
|
||||
- **Connection Security**: SSL/TLS support for production
|
||||
- **Role-based Access**: Maintained through user roles table
|
||||
|
||||
### 9. **Performance Considerations**
|
||||
|
||||
#### Query Optimization
|
||||
- Use of composite indexes
|
||||
- Efficient JOIN operations
|
||||
- Connection pooling (max 10 connections)
|
||||
- Query result caching with Redis
|
||||
- Lazy loading for associations
|
||||
|
||||
#### Database Configuration
|
||||
- InnoDB buffer pool tuning
|
||||
- Query cache optimization (MySQL 5.7)
|
||||
- Binary logging for replication
|
||||
- Slow query log monitoring
|
||||
|
||||
### 10. **Deployment Updates**
|
||||
|
||||
#### Development
|
||||
- Local MySQL instance
|
||||
- Sequelize migrations for schema management
|
||||
|
||||
#### Staging
|
||||
- Managed MySQL (AWS RDS, Azure Database, PlanetScale)
|
||||
- Automated migration deployment
|
||||
|
||||
#### Production
|
||||
- Read replicas for scaling
|
||||
- Automated backups (daily snapshots)
|
||||
- Point-in-time recovery
|
||||
- Connection pooling with ProxySQL (optional)
|
||||
|
||||
---
|
||||
|
||||
## What Stayed the Same
|
||||
|
||||
✅ **API Endpoints** - All endpoints remain unchanged
|
||||
✅ **Frontend Code** - No changes required to Angular app
|
||||
✅ **JWT Authentication** - Token strategy unchanged
|
||||
✅ **Business Logic** - Core features remain identical
|
||||
✅ **User Stories** - All acceptance criteria maintained
|
||||
|
||||
---
|
||||
|
||||
## Breaking Changes
|
||||
|
||||
⚠️ **Database Migration Required** - Cannot directly migrate MongoDB data to MySQL without transformation
|
||||
⚠️ **ORM Changes** - All Mongoose code must be rewritten to Sequelize
|
||||
⚠️ **Array Queries** - MongoDB array operations need to be rewritten for JSON columns or junction tables
|
||||
⚠️ **Aggregation Pipelines** - Complex MongoDB aggregations need to be rewritten as SQL JOINs and GROUP BY
|
||||
|
||||
---
|
||||
|
||||
## Data Migration Steps
|
||||
|
||||
If migrating existing MongoDB data:
|
||||
|
||||
1. **Export MongoDB Data**
|
||||
```bash
|
||||
mongoexport --db interview_quiz --collection users --out users.json
|
||||
mongoexport --db interview_quiz --collection questions --out questions.json
|
||||
# ... export all collections
|
||||
```
|
||||
|
||||
2. **Transform Data**
|
||||
- Convert ObjectIds to UUIDs
|
||||
- Flatten embedded documents
|
||||
- Split arrays into junction tables
|
||||
- Map MongoDB types to MySQL types
|
||||
|
||||
3. **Import to MySQL**
|
||||
```bash
|
||||
# Use custom Node.js script to import transformed data
|
||||
node scripts/import-from-mongodb.js
|
||||
```
|
||||
|
||||
---
|
||||
|
||||
## Testing Checklist
|
||||
|
||||
- [ ] All database tables created successfully
|
||||
- [ ] Foreign key constraints working
|
||||
- [ ] Indexes created and optimized
|
||||
- [ ] User registration and login working
|
||||
- [ ] Guest session management working
|
||||
- [ ] Quiz session creation and completion
|
||||
- [ ] Question CRUD operations (admin)
|
||||
- [ ] Bookmark functionality
|
||||
- [ ] Achievement system
|
||||
- [ ] Full-text search on questions
|
||||
- [ ] Dashboard statistics queries
|
||||
- [ ] Performance testing (1000+ concurrent users)
|
||||
- [ ] Backup and restore procedures
|
||||
- [ ] Migration rollback testing
|
||||
|
||||
---
|
||||
|
||||
## Additional Resources
|
||||
|
||||
### Sequelize Documentation
|
||||
- [Sequelize Official Docs](https://sequelize.org/docs/v6/)
|
||||
- [Migrations Guide](https://sequelize.org/docs/v6/other-topics/migrations/)
|
||||
- [Associations](https://sequelize.org/docs/v6/core-concepts/assocs/)
|
||||
|
||||
### MySQL Documentation
|
||||
- [MySQL 8.0 Reference](https://dev.mysql.com/doc/refman/8.0/en/)
|
||||
- [InnoDB Storage Engine](https://dev.mysql.com/doc/refman/8.0/en/innodb-storage-engine.html)
|
||||
- [Performance Tuning](https://dev.mysql.com/doc/refman/8.0/en/optimization.html)
|
||||
|
||||
---
|
||||
|
||||
## Version Information
|
||||
|
||||
- **Document Version**: 2.0 - MySQL Edition
|
||||
- **Migration Date**: November 2025
|
||||
- **Database**: MySQL 8.0+
|
||||
- **ORM**: Sequelize 6.x
|
||||
- **Node.js**: 18+
|
||||
|
||||
---
|
||||
|
||||
**Migration completed successfully!** 🎉
|
||||
Reference in New Issue
Block a user