add: Add CrudRepository interface with native_query decorator

Author: William Chen

example.py

@@ -0,0 +1,26 @@
+from sqlmodel import Field, SQLModel
+from sqlmodel.repository.crud_repository import CrudRepository, native_query
+
+
+class Hero(SQLModel, table=True):
+    id: int | None = Field(default=None, primary_key=True)
+    name: str
+    secret_name: str
+    age: int | None = None
+
+
+class HeroRepository(CrudRepository[int, Hero]):
+    @native_query("SELECT * FROM hero WHERE name = '{name}'", Hero)
+    def get_hero_by_name(self, name: str) -> Hero:
+        ...
+
+sqlite_file_name = "database.db"
+sqlite_url = f"sqlite:///{sqlite_file_name}"
+engine = CrudRepository.create_all_tables(sqlite_url)
+
+hero_repo = HeroRepository(engine)
+
+deadpond = Hero(name="Deadpond", secret_name="Dive Wilson")
+hero_repo.save(deadpond)
+print(hero_repo.find_all())
+print(hero_repo.get_hero_by_name(name="Deadpond"))

sqlmodel/repository/crud_repository.py

@@ -0,0 +1,102 @@
+
+
+from typing import Any, Callable, Generic, Iterable, Optional, Type, TypeVar, get_args
+from sqlalchemy.sql import text
+from uuid import UUID
+
+from pydantic import BaseModel
+from sqlalchemy import Engine, create_engine
+from sqlmodel import Session, SQLModel, select
+ 
+T = TypeVar("T", SQLModel, BaseModel)
+ID = TypeVar("ID", UUID,int)
+
+import logging
+
+logger = logging.getLogger(__name__)
+
+class CrudRepository(Generic[ID,T]):
+    def __init__(self, engine: Engine) -> None:
+        self.engine = engine
+        self.id_type ,self.model_class = self._get_model_id_type_with_class()
+        
+    @classmethod
+    def create_all_tables(cls, url: str) -> Engine:
+        engine = create_engine(url, echo=False)
+        SQLModel.metadata.create_all(engine)
+        return engine
+        
+    @classmethod
+    def _get_model_id_type_with_class(cls) -> tuple[Type[ID], Type[T]]:
+        return get_args(tp= cls.__mro__[0].__orig_bases__[0])
+
+    def _commit_operation_in_session(self,session_operation: Callable[[Session], None], session: Session) -> bool:
+        try:
+            session_operation(session)
+            session.commit()
+        except Exception as error:
+            logger.error(error)
+            return False
+        
+        return True
+
+    def _create_session(self) -> Session:
+        return Session(self.engine, expire_on_commit= True)
+
+    
+    def find_by_id(self, id: ID) -> tuple[T, Session]:
+        session = self._create_session()
+        statement = select(self.model_class).where(self.model_class.id == id)  # type: ignore
+        return (session.exec(statement).one(), session)
+
+    def find_all_by_ids(self, ids: list[ID]) -> tuple[Iterable[T], Session]:
+        session = self._create_session()
+        statement = select(self.model_class).where(self.model_class.id in ids)  # type: ignore
+        return (session.exec(statement).all(), session)
+    
+
+    def find_all(self) -> tuple[Iterable[T], Session]:
+        session = self._create_session()
+        statement = select(self.model_class) # type: ignore
+        return (session.exec(statement).all(), session)
+
+    def save(self, entity: T, session: Optional[Session] = None) -> T:
+        self._commit_operation_in_session(lambda session: session.add(entity), session or self._create_session())
+        return entity
+
+    def save_all(self, entities: Iterable[T], session: Optional[Session] = None) -> bool:
+        return self._commit_operation_in_session(
+            lambda session: session.add_all(entities), session or self._create_session()
+        )
+
+    def delete(self, entity: T, session: Optional[Session] = None) -> bool:
+        return self._commit_operation_in_session(
+            lambda session: session.delete(entity), session or self._create_session()
+        )
+    
+    def delete_all(self, entities: Iterable[T], session: Optional[Session] = None) -> bool:
+        session = session or self._create_session()
+        for entity in entities:
+            session.delete(entity)
+        session.commit()
+
+        return True
+    
+    
+def native_query(query: str, return_type: Type[T]) -> Any:
+    def decorated(func: Callable[..., T]) -> Callable[..., T]:
+        def wrapper(self: CrudRepository, **kwargs) -> T:
+            with self.engine.connect() as connection:
+                
+                
+                sql= text(query.format(**kwargs))
+                query_result = connection.execute(sql)
+                query_result_dicts = query_result.mappings().all()
+                if return_type.__name__ == "Iterable":
+                    cls_inside_inside_iterable = get_args(return_type)[0]
+                    return [cls_inside_inside_iterable.model_validate(query_result) for query_result in query_result_dicts] # type: ignore
+                return return_type.model_validate(list(query_result_dicts).pop())  # Create an instance of the specified model class
+            # return model_instance
+        return wrapper
+    return decorated # type: ignore
+