add database but need to test it

db/database.py

@@ -0,0 +1,9 @@
+from sqlalchemy import create_engine, engine
+from sqlalchemy.orm import sessionmaker, declarative_base
+
+DATABASE_URL = "sqlite:///./urls.db"
+
+engine = create_engine(DATABASE_URL, connect_args={"check_same_thread": False})
+SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)
+
+Base = declarative_base()