add database but need to test it

db/crud.py

@@ -0,0 +1,18 @@
+from pydantic import Secret
+import sqlalchemy.orm import Session
+from . import models
+
+def create_url(db:Session, short_code:str , long_url:str):
+    db_url = models.URL(
+        short_code=short_code,
+        long_url=long_url
+    )
+    db.add(db_url)
+    db.commit()
+    db.refresh(db_url)
+    return db_url
+
+def get_url(db:Session , short_code:str):
+    return db.query(models.URL).filter(
+        models.URL.short_code == short_code
+    ).first()