Updated code example

2024/sqlalchemy/oop_approach.py

@@ -1,31 +1,31 @@
 import sqlalchemy as sa
 from sqlalchemy.orm import Mapped, mapped_column, sessionmaker, declarative_base
 
-db = sa.create_engine('sqlite:///:memory:')
-Session = sessionmaker(bind = db)
+db = sa.create_engine("sqlite:///:memory:")
+Session = sessionmaker(bind=db)
 Base = declarative_base()
 
 
 class User(Base):
-    __tablename__ = 'users'
+    __tablename__ = "users"
 
-    id: Mapped[int] = mapped_column(primary_key = True)
-    username: str = sa.Column(sa.String)
-    email: str = sa.Column(sa.String)
+    id: Mapped[int] = mapped_column(primary_key=True)
+    username: Mapped[str]
+    email: Mapped[str]
 
     def __repr__(self) -> str:
-        return f'<User(username={self.username}, email={self.email})>'
+        return f"<User(id={self.id}, username={self.username}, email={self.email})>"
 
 
 def main() -> None:
     Base.metadata.create_all(db)
-    user = User(username = 'Arjan', email = "[email protected]")
+    user = User(username="Arjan", email="[email protected]")
 
     with Session() as session:
         session.add(user)
         session.commit()
         print(session.query(User).all())
 
 
-if __name__ == '__main__':
+if __name__ == "__main__":
     main()

2024/sqlalchemy/relationship.py

@@ -1,36 +1,48 @@
 import hashlib
 import typing
 import sqlalchemy as sa
-from sqlalchemy.orm import declarative_base, mapped_column, relationship, sessionmaker, Mapped
-
-db = sa.create_engine('sqlite:///:memory:')
-Session = sessionmaker(bind = db)
+from sqlalchemy.orm import (
+    declarative_base,
+    mapped_column,
+    relationship,
+    sessionmaker,
+    Mapped,
+)
+
+db = sa.create_engine("sqlite:///:memory:")
+Session = sessionmaker(bind=db)
 Base = declarative_base()
 
 
 class User(Base):
-    __tablename__ = 'users'
-    id: Mapped[int] = mapped_column(primary_key = True)
-    auth: Mapped["UserAuth"] = relationship('UserAuth', uselist = False, back_populates = 'user')
-    posts: Mapped[typing.List["UserPost"]] = relationship('UserPost', back_populates = 'user')
+    __tablename__ = "users"
+    id: Mapped[int] = mapped_column(primary_key=True)
+    auth: Mapped["UserAuth"] = relationship(
+        "UserAuth", uselist=False, back_populates="user"
+    )
+    posts: Mapped[typing.List["UserPost"]] = relationship(
+        "UserPost", back_populates="user"
+    )
 
     def __init__(self, username: str, email: str, password: str):
         super().__init__()
-        self.auth = UserAuth(username = username, email = email)
+        self.auth = UserAuth(username=username, email=email)
         self.auth.set_password(password)
 
     def __repr__(self) -> str:
-        return f'<User(username={self.auth.username}, email={self.auth.email})>'
+        return f"<User(username={self.auth.username}, email={self.auth.email})>"
 
 
 class UserAuth(Base):
-    __tablename__ = 'user_auth'
+    __tablename__ = "user_auth"
 
-    id: int = sa.Column(sa.Integer, sa.ForeignKey('users.id'), primary_key = True, index = True, unique = True)
+    id: int = sa.Column(
+        sa.Integer, sa.ForeignKey("users.id"), primary_key=True, index=True, unique=True
+    )
     username: str = sa.Column(sa.String)
-    email: str = sa.Column(sa.String, unique = True)
+    email: str = sa.Column(sa.String, unique=True)
     password_hash: str = sa.Column(sa.String)
-    user: Mapped["User"] = relationship('User', back_populates = 'auth')
+    user: Mapped["User"] = relationship("User", back_populates="auth")
 
     def __init__(self, username: str, email: str):
         self.username = username
@@ -43,26 +55,28 @@ def check_password(self, password: str) -> bool:
         return self.password_hash == hashlib.sha256(password.encode()).hexdigest()
 
     def __repr__(self) -> str:
-        return f'<UserAuth(username={self.username}, email={self.email})>'
+        return f"<UserAuth(username={self.username}, email={self.email})>"
 
 
 class UserPost(Base):
-    __tablename__ = 'user_posts'
-    id: int = sa.Column(sa.Integer, primary_key = True)
-    user_id: int = sa.Column(sa.Integer, sa.ForeignKey('users.id'), nullable = False, index = True)
+    __tablename__ = "user_posts"
+    id: int = sa.Column(sa.Integer, primary_key=True)
+    user_id: int = sa.Column(
+        sa.Integer, sa.ForeignKey("users.id"), nullable=False, index=True
+    )
     content: str = sa.Column(sa.String)
-    user: Mapped["User"] = relationship('User', back_populates = 'posts')
+    user: Mapped["User"] = relationship("User", back_populates="posts")
 
     def __repr__(self) -> str:
-        return f'<UserPost(user={self.user}, content={self.content})>'
+        return f"<UserPost(user={self.user}, content={self.content})>"
 
 
 def main() -> None:
     Base.metadata.create_all(db)
 
     with Session.begin() as session:
-        user = User(username = 'Arjan', email = "[email protected]", password = "password")
-        post = UserPost(content = 'Hello World!', user = user)
+        user = User(username="Arjan", email="[email protected]", password="password")
+        post = UserPost(content="Hello World!", user=user)
         session.add(user)
         session.add(post)
 
@@ -79,5 +93,5 @@ def main() -> None:
         print(posts)
 
 
-if __name__ == '__main__':
+if __name__ == "__main__":
     main()

2024/sqlalchemy/simple_approach.py

@@ -1,24 +1,25 @@
 import sqlalchemy as sa
 
-engine = sa.create_engine('sqlite:///:memory:')
+engine = sa.create_engine("sqlite:///:memory:")
 connection = engine.connect()
 
 metadata = sa.MetaData()
 
 user_table = sa.Table(
-        'user', metadata,
-        sa.Column('id', sa.Integer, primary_key = True),
-        sa.Column('username', sa.String),
-        sa.Column('email', sa.String),
+    "user",
+    metadata,
+    sa.Column("id", sa.Integer, primary_key=True),
+    sa.Column("username", sa.String),
+    sa.Column("email", sa.String),
 )
 
 
-def insert_user(username:str, email:str) -> None:
-    query = user_table.insert().values(username = username, email = email)
+def insert_user(username: str, email: str) -> None:
+    query = user_table.insert().values(username=username, email=email)
     connection.execute(query)
 
 
-def select_user(username:str) -> sa.engine.Result:
+def select_user(username: str) -> sa.engine.Result:
     query = user_table.select().where(user_table.c.username == username)
     result = connection.execute(query)
     return result.fetchone()
@@ -31,5 +32,5 @@ def main() -> None:
     connection.close()
 
 
-if __name__ == '__main__':
+if __name__ == "__main__":
     main()