feat: finish app page

src/content/docs/guides/python/flask/app.mdx

@@ -147,34 +147,55 @@ Update the `__init__.py` file to register the blueprint.
         return "pong!"
 ```
 
-## Setting up the db
+## Setting up the database
 
-Create a new file called `db.py` and add the following code to it.
+Following from how we set up the blog blueprint, we can create a new file called `db.py` and add the following code to it.
 
 ```python
 // flaskapp/db.py
-import sqlite3
-from flask import current_app, g, Flask
+from flask import Flask
+from flask_sqlalchemy import SQLAlchemy
+from sqlalchemy.orm import DeclarativeBase
 
-def get_db():
-    """Get a new database connection. If one already exists, use that one."""
-    if 'db' not in g:
-        g.db = sqlite3.connect(current_app.config["DATABASE"])
-        g.db.row_factory = sqlite3.Row
-    return g.db
+class Base(DeclarativeBase):
+    pass
 
-def close_db(e=None):
-    """Close the database connection if it exists."""
-    db = g.pop("db")
+db = SQLAlchemy(model_class=Base)
 
-    if db is not None:
-        db.close()
+class Post(db.Model):
+    id = db.Column(db.Integer, primary_key=True)
+    title = db.Column(db.String(100), nullable=False)
+    content = db.Column(db.Text, nullable=False)
 
 def init_app(app: Flask):
-    """Register the close_db function with the Flask app."""
-    app.teardown_appcontext(close_db)
+    db.init_app(app)
+    with app.app_context():
+        db.create_all()
 ```
 
+<Steps>
+
+1. The `Base` class is created as a base for the databases
+
+2. The `db` object is created
+
+   The `db` object is created using the `SQLAlchemy` class.
+   The `model_class` parameter is set to the `Base` class to use it as the base for all models.
+
+3. The `Post` model is created
+
+    The `Post` model is created with an `id`, `title`, and `content` column.
+    The `id` column is the primary key.
+    The `title` and `content` columns are set to be not nullable.
+
+4. The `init_app` function is created
+
+    The `init_app` function is created to initialise the database.
+    The `db` object is initialised with the app.
+    The database is created with the `create_all` method.
+
+</Steps>
+
 In the `__init__.py` file, import the `db` module and call the `init_app` function.
 
 ```diff lang="python"
@@ -190,49 +211,18 @@ In the `__init__.py` file, import the `db` module and call the `init_app` functi
     app.register_blueprint(blog)
 ```
 
-## Database Setup
-
-While we have the database setup we need to create the tables. We can do this by creating a new file called `schema.sql`.
-
-```sql
-// flaskapp/schema.sql
-DROP TABLE IF EXISTS post;
-CREATE TABLE post (
-    id INTEGER PRIMARY KEY AUTOINCREMENT,
-    title TEXT NOT NULL,
-    body TEXT NOT NULL
-);
-```
-
-
+With the database set up, we can now add a route to add a post to the database.
 
 ```diff lang="python"
-// flaskapp/__init__.py
-+def init_db():
-+    """Create and fill the db."""
-+    db = get_db()
-+
-+    with current_app.open_resource("schema.sql") as f:
-+        db.executescript(f.read().decode("utf8"))
-
-
-+@click.command("init-db")
-+def init_db_command():
-+    """Clear the existing data and create new tables."""
-+    init_db()
-+    click.echo("Initialized the database.")
-
-def init_app(app):
-    """Add teardown and cli on app creation."""
-    app.teardown_appcontext(close_db)
-+    app.cli.add_command(init_db_command)
-```
+// flaskapp/blog.py
++ from .db import Post, db
 
-As we have now integrated our database into our app we can now initialise it. To do this we can run the following command:
+...
 
-```bash
-$ flask --app flaskapp init-db
-Initialized the database.
++@bp.route("/add_post")
++def add_post():
++    post = Post(title="Hello World", content="This is my first post")
++    db.session.add(post)
++    db.session.commit()
++    return "Post added"
 ```
-
-You should now be able to see a flaskapp.sqlite file in the instance folder in your project which is your newly created database.

src/content/docs/guides/python/flask/database.mdx

@@ -235,7 +235,7 @@ db.session.commit()
 
 #### Using SQLAlchemy to setup the database
 
-We can also use SQLAlchemy to create the database and tables for us. We can use the `create_all` method to create the tables:
+We can also use SQLAlchemy to create the database and tables for us. We can use the `create_all` method to create the tables. If the tables already exist, this method will not do anything.
 
 ```python
 with app.app_context():