python中flask mysql fetchall的问题

...
from flaskext.mysql import MySQL
...
app = Flask(__name__)
mysql=MySQL(app)
# config mysql
app.config['MYSQL_DATABASE_HOST'] = '****'
app.config['MYSQL_DATABASE_USER'] = '****'
app.config['MYSQL_DATABASE_PASSWORD'] = '****'
app.config['MYSQL_DATABASE_DB'] = '****'
app.config['MYSQL_DATABASE_PORT'] = ****
# Init
mysql.init_app(app)

...

@app.route('/myapps')
@is_logged_in
def myapps():
    cur = mysql.get_db().cursor()
    username = session['username']
    result = cur.execute("select * from appointments where username= %s",[username])
    if result > 0:
        myapps = cur.fetchall()
        return render_template('myapps.html', myapps = myapps)
    else:
        msg = 'No appointments found'
        return render_template('myapps.html', msg=msg)
    cur.close()

<tbody>
            {% for app in myapps %}
          <tr>
            <th scope="row">{{app.app_id}}</th>
            <td>{{app.services}}</td>
            <td>{{app.start_date}}</td>
            <td>{{app.end_date}}</td>
            <td>{{app.start_hour}}</td>
            <td>{{app.end_hour}}</td>
            <td>{{app.creation_date}}</td>
            <td>{{app.username}}</td>
          </tr>
          {% endfor %}
        </tbody>