Implement working SQLAlchemy DB adapter

fastapi_users/db/sqlalchemy.py

@@ -0,0 +1,44 @@
+from typing import List
+
+from databases import Database
+from sqlalchemy import Boolean, Column, String
+from sqlalchemy.ext.declarative import declarative_base
+
+from fastapi_users.db import UserDBInterface
+from fastapi_users.models import UserDB
+
+Base = declarative_base()
+
+
+class User(Base):
+    __tablename__ = 'user'
+
+    id = Column(String, primary_key=True)
+    email = Column(String, unique=True, index=True)
+    hashed_password = Column(String)
+    is_active = Column(Boolean, default=True)
+    is_superuser = Column(Boolean, default=False)
+
+
+users = User.__table__
+
+
+class SQLAlchemyUserDB(UserDBInterface):
+
+    database: Database
+
+    def __init__(self, database):
+        self.database = database
+
+    async def list(self) -> List[UserDB]:
+        query = users.select()
+        return await self.database.fetch_all(query)
+
+    async def get_by_email(self, email: str) -> UserDB:
+        query = users.select().where(User.email == email)
+        return await self.database.fetch_one(query)
+
+    async def create(self, user: UserDB) -> UserDB:
+        query = users.insert().values(**user.dict())
+        await self.database.execute(query)
+        return user