Comenzando a utilizar SQLAlchemy

Tuve que reescribir bastante para lograrlo, pero ya funciona :3

files/about.py

@@ -1,9 +1,9 @@
-from files.db import get_db
-
 from flask import Blueprint, request, render_template, redirect, url_for, flash
+from files.models import db, Message
 
 bp = Blueprint('about', __name__, url_prefix='/about')
 
+
 @bp.route('/', methods=('GET', 'POST'))
 def about():
     if request.method == 'POST':
@@ -11,7 +11,6 @@ def about():
         email = request.form['email']
         message = request.form['message']
 
-        db = get_db()
         error = None
 
         if not name:
@@ -20,21 +19,18 @@ def about():
             error = 'Missing email'
         elif not message:
             error = 'Empty message'
-            
+
         if error is not None:
             flash(error)
         else:
-            db.execute(
-                'INSERT INTO messages'
-                ' (name, email, message)'
-                ' VALUES (?, ?, ?)',
-                (name, email, message)
-            )
-            db.commit()
-            return redirect(url_for('about.thanks')) 
+            m = Message(name, email, message)
+            db.session.add(m)
+            db.session.commit()
+            return redirect(url_for('about.thanks'))
 
     return render_template('about/about.html')
 
+
 @bp.route('/thanks')
 def thanks():
     return render_template('about/thanks.html')