feat: crud and backups are working

backend/app/database.py

@@ -0,0 +1,11 @@
+from sqlalchemy import create_engine
+from sqlalchemy.orm import sessionmaker, declarative_base
+import os
+
+DATABASE_URL = os.getenv(
+    "DATABASE_URL", "postgresql://user:password@db:5432/mydatabase"
+)
+
+engine = create_engine(DATABASE_URL)
+SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)
+Base = declarative_base()