add db migration

README.md

@@ -316,14 +316,65 @@ uvicorn main:app --port 8001
 ```
 
 ### Database errors
-Delete the database file and restart:
+If you encounter database errors, try the following:
+
+**With Migrations (Recommended):**
 ```bash
-rm data/youmusic.db
-docker-compose restart
+# Check current migration status
+cd backend
+./migrate.sh current
+
+# Apply pending migrations
+./migrate.sh upgrade
+
+# If needed, check migration history
+./migrate.sh history
 ```
 
+**Reset Database (Dev only - DATA LOSS!):**
+```bash
+# Delete database and restart (auto-migrates on startup)
+rm data/youmusic.db
+docker-compose restart
+
+# Or for local development
+./dev-stop.sh
+rm backend/data/youmusic.db
+./dev.sh
+```
+
+See [MIGRATIONS.md](MIGRATIONS.md) for detailed migration documentation.
+
 ## Development
 
+### Database Migrations
+
+YouMusic uses Alembic for database migrations. This allows safe schema changes without data loss.
+
+**Common operations:**
+```bash
+cd backend
+
+# View current database version
+./migrate.sh current
+
+# Create a new migration after modifying models
+./migrate.sh create "Add new field description"
+
+# Apply migrations
+./migrate.sh upgrade
+
+# Rollback last migration
+./migrate.sh downgrade
+
+# View migration history
+./migrate.sh history
+```
+
+**Note:** Migrations run automatically on app startup, so manual migration is only needed when developing new schema changes.
+
+For complete migration documentation, see [MIGRATIONS.md](MIGRATIONS.md).
+
 ### Running tests
 ```bash
 # Backend