# Database Variable Migration Complete ✅

## Summary

All database configuration variables across the entire project have been successfully unified to use the `DB_*` prefix.

## Files Updated

### Configuration Files
- ✅ `.env.example` - Updated with unified `DB_*` variables
- ✅ `docker-compose.yml` - Uses `DB_*` variables with proper MySQL container mapping

### Documentation Files
- ✅ `QUICK_START.md` - All references updated
- ✅ `DATABASE_SETUP.md` - All references updated
- ✅ `DEPLOYMENT_SUMMARY.md` - All references updated
- ✅ `DEPLOYMENT_GUIDE.md` - Docker compose example and GitHub Actions updated
- ✅ `LOCAL_TESTING.md` - All references updated

### Migration Tools
- ✅ `scripts/migrate-db-vars.sh` - Helper script for existing installations
- ✅ `docs/DB_VARIABLE_MIGRATION.md` - Comprehensive migration guide
- ✅ `DB_VARS_UNIFIED.md` - Quick reference guide

### Application Code
- ✅ `apps/api/src/db.ts` - Already using `DB_*` (no changes needed)
- ✅ `apps/api/drizzle.config.ts` - Already using `DB_*` (no changes needed)
- ✅ `apps/api/src/db/migrate.ts` - Already using `DB_*` (no changes needed)

## Unified Variable Names

| Variable | Purpose | Default |
|----------|---------|---------|
| `DB_ROOT_PASSWORD` | MySQL root password | - |
| `DB_PASSWORD` | Application database password | - |
| `DB_USER` | Database username | `voxblog` |
| `DB_NAME` | Database name | `voxblog` |
| `DB_HOST` | Database host | `mysql` (docker) / `localhost` |
| `DB_PORT` | Database port | `3306` |

## What Was Changed

### Before
```bash
# Mixed naming conventions
MYSQL_ROOT_PASSWORD=xxx
MYSQL_PASSWORD=xxx
DATABASE_URL=mysql://...
DB_HOST=mysql
DB_PORT=3306
DB_USER=voxblog
DB_PASSWORD=xxx  # Duplicate!
DB_NAME=voxblog
```

### After
```bash
# Unified DB_* naming
DB_ROOT_PASSWORD=xxx
DB_PASSWORD=xxx
DB_USER=voxblog
DB_NAME=voxblog
DB_HOST=mysql
DB_PORT=3306
```

## Benefits Achieved

1. ✅ **Consistency** - Single naming pattern across entire codebase
2. ✅ **Simplicity** - No more confusion about which variable to use
3. ✅ **No Duplication** - Removed redundant `DATABASE_URL` and duplicate password variables
4. ✅ **Better Defaults** - All variables have sensible defaults in docker-compose
5. ✅ **Clear Documentation** - All docs updated with correct variable names
6. ✅ **Easy Migration** - Script provided for existing installations

## Verification

Run this to verify no legacy variables remain in your project:
```bash
# Should only show references in migration docs (as "before" examples)
grep -r "MYSQL_ROOT_PASSWORD\|MYSQL_PASSWORD" --include="*.md" --include="*.yml" --include="*.env*" .
```

## Next Steps for Users

### New Installations
Just use the updated `.env.example`:
```bash
cp .env.example .env
# Edit .env with your values
docker-compose up -d
```

### Existing Installations
Run the migration script:
```bash
./scripts/migrate-db-vars.sh
docker-compose down
docker-compose up -d
```

## Technical Notes

### MySQL Container Mapping
The MySQL Docker container still requires `MYSQL_*` environment variables internally. Our `docker-compose.yml` handles this mapping:

```yaml
mysql:
  environment:
    MYSQL_ROOT_PASSWORD: ${DB_ROOT_PASSWORD}  # Maps DB_* to MYSQL_*
    MYSQL_PASSWORD: ${DB_PASSWORD}
    MYSQL_USER: ${DB_USER:-voxblog}
    MYSQL_DATABASE: ${DB_NAME:-voxblog}
```

This is transparent to users - they only need to set `DB_*` variables.

### Application Code
The application code in `apps/api/src/db.ts` and related files already used `DB_*` variables, so no code changes were needed. This migration was purely about configuration consistency.

## Rollback (If Needed)

If you need to rollback for any reason:
```bash
# Restore your .env backup
cp .env.backup.YYYYMMDD_HHMMSS .env

# Or manually change:
DB_ROOT_PASSWORD → MYSQL_ROOT_PASSWORD
DB_PASSWORD → MYSQL_PASSWORD
```

However, we recommend moving forward with the unified naming as it's cleaner and more maintainable.

## Support

- See `docs/DB_VARIABLE_MIGRATION.md` for detailed migration guide
- See `DB_VARS_UNIFIED.md` for quick reference
- Check docker-compose logs if services don't start: `docker-compose logs`

---

**Migration completed successfully!** 🎉

All database variables are now unified under the `DB_*` prefix for consistency and simplicity.