add database but need to test it

db/models.py

@@ -0,0 +1,14 @@
+from sqlalchemy import Column, Integer, String, DateTime
+from datetime import datetime
+
+from sqlalchemy.sql.traversals import ColIdentityComparatorStrategy
+from .database import Base
+
+
+class URL(Base):
+    __tablename__ = "urls"
+
+    id = Column(Integer, primary_key=True, index=True)
+    short_code = Column(String, unique=True, index=True)
+    long_url = Column(String)
+    create_at = Column(DateTime, default=datetime.utcnow)