update examples to SQLAlchemy 2 style

Author: pamelafox

examples/flaskr/README.rst

@@ -12,7 +12,7 @@ Install
 
 **Be sure to use the same version of the code as the version of the docs
 you're reading.** You probably want the latest tagged version, but the
-default Git version is the master branch.
+default Git version is the main branch.
 
 .. code-block:: text
 
@@ -42,7 +42,7 @@ Install Flaskr:
 
     $ pip install -e .
 
-Or if you are using the master branch, install Flask-SQLAlchemy from
+Or if you are using the main branch, install Flask-SQLAlchemy from
 source before installing Flaskr:
 
 .. code-block:: text
@@ -79,7 +79,7 @@ Test
 .. code-block:: text
 
     $ pip install -e '.[test]'
-    $ pytest
+    $ python3 -m pytest
 
 Run with coverage report:
 

examples/flaskr/flaskr/__init__.py

@@ -4,10 +4,16 @@
 from flask import Flask
 from flask.cli import with_appcontext
 from flask_sqlalchemy import SQLAlchemy
+from sqlalchemy.orm import DeclarativeBase
 
-__version__ = (1, 0, 0, "dev")
+__version__ = (1, 1, 0, "dev")
 
-db = SQLAlchemy()
+
+class Base(DeclarativeBase):
+    pass
+
+
+db = SQLAlchemy(model_class=Base)
 
 
 def create_app(test_config=None):

examples/flaskr/flaskr/auth/models.py

@@ -1,22 +1,29 @@
+from __future__ import annotations
+
+from typing import TYPE_CHECKING
+
+from sqlalchemy.orm import Mapped, mapped_column, relationship
 from werkzeug.security import check_password_hash
 from werkzeug.security import generate_password_hash
 
 from flaskr import db
 
+if TYPE_CHECKING:
+    from ..blog.models import Post
 
-class User(db.Model):
-    id = db.Column(db.Integer, primary_key=True)
-    username = db.Column(db.String, unique=True, nullable=False)
-    password_hash = db.Column(db.String, nullable=False)
 
-    posts = db.relationship("Post", back_populates="author")
+class User(db.Model):
+    id: Mapped[int] = mapped_column(primary_key=True)
+    username: Mapped[str] = mapped_column(unique=True)
+    password_hash: Mapped[str]
+    posts: Mapped[list[Post]] = relationship("Post", back_populates="author")
 
-    def set_password(self, value):
+    def set_password(self, value: str) -> None:
         """Store the password as a hash for security."""
         self.password_hash = generate_password_hash(value)
 
     # allow password = "..." to set a password
     password = property(fset=set_password)
 
-    def check_password(self, value):
+    def check_password(self, value: str) -> bool:
         return check_password_hash(self.password_hash, value)

examples/flaskr/flaskr/blog/models.py

@@ -1,3 +1,5 @@
+from sqlalchemy.orm import Mapped, mapped_column, relationship
+from sqlalchemy import ForeignKey
 from datetime import datetime
 from datetime import timezone
 
@@ -7,25 +9,25 @@
 from flaskr.auth.models import User
 
 
-def now_utc():
+def now_utc() -> datetime:
     return datetime.now(timezone.utc)
 
 
 class Post(db.Model):
-    id = db.Column(db.Integer, primary_key=True)
-    author_id = db.Column(db.ForeignKey(User.id), nullable=False)
-    created = db.Column(db.DateTime, nullable=False, default=now_utc)
-    title = db.Column(db.String, nullable=False)
-    body = db.Column(db.String, nullable=False)
+    id: Mapped[int] = mapped_column(primary_key=True)
+    author_id: Mapped[int] = mapped_column(ForeignKey("user.id"))
+    created: Mapped[datetime] = mapped_column(default=now_utc)
+    title: Mapped[str]
+    body: Mapped[str]
 
     # User object backed by author_id
     # lazy="joined" means the user is returned with the post in one query
-    author = db.relationship(User, lazy="joined", back_populates="posts")
+    author: Mapped[User] = relationship(lazy="joined", back_populates="posts")
 
     @property
-    def update_url(self):
+    def update_url(self) -> str:
         return url_for("blog.update", id=self.id)
 
     @property
-    def delete_url(self):
+    def delete_url(self) -> str:
         return url_for("blog.delete", id=self.id)

examples/flaskr/setup.cfg

@@ -15,8 +15,7 @@ include_package_data = true
 python_requires = >= 3.8
 install_requires =
     Flask>=2.2
-    Flask-SQLAlchemy>=3
-    SQLAlchemy>=1.4.18
+    Flask-SQLAlchemy>=3.1.0
 
 [options.extras_require]
 test =

examples/todo/app.py

@@ -8,23 +8,32 @@
 from flask import request
 from flask import url_for
 from flask_sqlalchemy import SQLAlchemy
+from sqlalchemy.orm import DeclarativeBase
+from sqlalchemy.orm import Mapped, mapped_column
+
 
 app = Flask(__name__)
 app.secret_key = "Achee6phIexoh8dagiQuew0ephuga4Ih"
 app.config["SQLALCHEMY_DATABASE_URI"] = "sqlite:///todo.sqlite"
-db = SQLAlchemy(app)
 
 
-def now_utc():
+class Base(DeclarativeBase):
+    pass
+
+
+db = SQLAlchemy(app, model_class=Base)
+
+
+def now_utc() -> datetime:
     return datetime.now(timezone.utc)
 
 
 class Todo(db.Model):
-    id = db.Column(db.Integer, primary_key=True)
-    title = db.Column(db.String, nullable=False)
-    text = db.Column(db.String, nullable=False)
-    done = db.Column(db.Boolean, nullable=False, default=False)
-    pub_date = db.Column(db.DateTime, nullable=False, default=now_utc)
+    id: Mapped[int] = mapped_column(primary_key=True)
+    title: Mapped[str]
+    text: Mapped[str]
+    done: Mapped[bool] = mapped_column(default=False)
+    pub_date: Mapped[datetime] = mapped_column(default=now_utc)
 
 
 with app.app_context():