Use a Base table class for SQLAlchemy adapter

fastapi_users/db/sqlalchemy.py

@@ -1,16 +1,13 @@
 from typing import List
 
 from databases import Database
-from sqlalchemy import Boolean, Column, String
-from sqlalchemy.ext.declarative import declarative_base
+from sqlalchemy import Boolean, Column, String, Table
 
 from fastapi_users.db import BaseUserDatabase
 from fastapi_users.models import UserDB
 
-Base = declarative_base()
 
-
-class BaseUser(Base):
+class BaseUser:
     __tablename__ = "user"
 
     id = Column(String, primary_key=True)
@@ -20,34 +17,35 @@ class BaseUser(Base):
     is_superuser = Column(Boolean, default=False)
 
 
-users = BaseUser.__table__
-
-
 class SQLAlchemyUserDatabase(BaseUserDatabase):
 
     database: Database
+    users: Table
 
-    def __init__(self, database):
+    def __init__(self, database: Database, users: Table):
         self.database = database
+        self.users = users
 
     async def list(self) -> List[UserDB]:
-        query = users.select()
+        query = self.users.select()
         return await self.database.fetch_all(query)
 
     async def get(self, id: str) -> UserDB:
-        query = users.select().where(BaseUser.id == id)
+        query = self.users.select().where(self.users.c.id == id)
         return await self.database.fetch_one(query)
 
     async def get_by_email(self, email: str) -> UserDB:
-        query = users.select().where(BaseUser.email == email)
+        query = self.users.select().where(self.users.c.email == email)
         return await self.database.fetch_one(query)
 
     async def create(self, user: UserDB) -> UserDB:
-        query = users.insert().values(**user.dict())
+        query = self.users.insert().values(**user.dict())
         await self.database.execute(query)
         return user
 
     async def update(self, user: UserDB) -> UserDB:
-        query = users.update().where(BaseUser.id == user.id).values(**user.dict())
+        query = (
+            self.users.update().where(self.users.c.id == user.id).values(**user.dict())
+        )
         await self.database.execute(query)
         return user