Python Flask MySQL，UPDATE 查询有问题

Question

我刚开始使用 Python 进行一个新项目，我想就一个非常恼人的问题寻求帮助。

环境[Python，烧瓶，MySQL] 我目前正在开发一个 Web 应用程序（登录、用户信息管理、调查表）

当用户第一次在应用程序上注册时，用户名、密码、邮件地址被插入到数据库中。另外，由于我需要记录对调查表的每一个答案，我自动将 0 值分配给 Q001 和 Q002（问题）。

登录后，用户将开始回答调查，我只需要那些答案，以替换相应行内的值。我试图使用 UPDATE SET WHERE 查询，但我不断收到“格式字符串的参数不足”错误。这是python代码

poll_data = {
   'question1' : 'Are you a donkey?',
    'question2' : 'Are you a pig?',
} 
@app.route('/flaskProject/register', methods=['GET', 'POST'])
def register():
    # Output message if something goes wrong...
    msg = ''
    # Check if "username", "password" and "email" POST requests exist (user submitted form)
    if request.method == 'POST' and 'username' in request.form and 'password' in request.form and 'email' in request.form:
        # Create variables for easy access
        username = request.form['username']
        password = request.form['password']
        email = request.form['email']
        Q001 = 0
        Q002 = 0
        # Check if account exists using MySQL
        cursor = mysql.connection.cursor(MySQLdb.cursors.DictCursor)
        cursor.execute('SELECT * FROM accounts WHERE username = %s', (username,))
        account = cursor.fetchone()
        # If account exists show error and validation checks
        if account:
            msg = 'Account already exists!'
        elif not username or not password or not email:
            msg = 'Please fill out the form!'
        else:
            # Account doesn't exists and the form data is valid, now insert new account into accounts table
            cursor.execute('INSERT INTO accounts VALUES (NULL, %s, %s, %s, %s, %s)', (username, password, email, Q001, Q002, ))
            mysql.connection.commit()
            msg = 'You have successfully registered!'
    elif request.method == 'POST':
        # Form is empty... (no POST data)
        msg = 'Please fill out the form!'
    # Show registration form with message (if any)
    return render_template('register.html', msg=msg)   
@app.route("/flaskProject/questionnaire1", methods=['GET', 'POST'])
def questionnaire1():
    # Check if user is loggedin
    if request.method == 'POST' and 'loggedin' in session:
        # Create variables for easy access
        Q001 = request.form['Q001']
        Q002 = request.form['Q002']
        cursor = mysql.connection.cursor(MySQLdb.cursors.DictCursor)
        cursor.execute("UPDATE accounts SET Q001 = %s, Q002 = %s WHERE id = %s", (session['id'],))
        mysql.connection.commit()
        # Redirect to survey
    return render_template('questionnaire1.html', data=poll_data)

下面是我的BD

CREATE DATABASE IF NOT EXISTS `flaskProject` DEFAULT CHARACTER SET utf8 COLLATE utf8_general_ci;
USE `flaskProject`;

CREATE TABLE IF NOT EXISTS `accounts` (
    `id` int(11) NOT NULL AUTO_INCREMENT,
    `username` varchar(50) NOT NULL,
    `password` varchar(255) NOT NULL,
    `email` varchar(100) NOT NULL,
    'Q001' varchar(50) NOT NULL,
    'Q002' varchar(50) NOT NULL,
    PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=2 DEFAULT CHARSET=utf8;

INSERT INTO `accounts` (`id`, `username`, `password`, `email`, 'Q001', 'Q002') VALUES (1, 'test', 'test', 'test@test.com', '0', '0');

最后是调查页面html

 <form action="{{ url_for('questionnaire1') }}" method="post" autocomplete="off">
    <table style="width:100%">
  <tr>
    <td>{{ data.question1 }}</td>
    <td style="text-align:right">
        <label for="Q001"></label>
            <input type="text" name="Q001" placeholder="Q001" id="Q001" required></td>
  </tr>
  <tr>
    <td>{{ data.question2 }}</td>
    <td style="text-align:right">
        <label for="Q002"></label>
            <input type="text" name="Q002" placeholder="Q002" id="Q002" required></td>
  <tr>
    <td></td>
    <td></td>
    <td></td>
  </tr>
</table>
<br>
        <div class="msg">{{ msg }}</div>
  <input type="submit" value="Next">
    </form>

Answer 1

对于每个占位符 - %s - 在你的查询中，你需要在元组中提供一个变量，它是 .execute().

的第二个参数

您拥有所需的变量，只是您尚未提供它们。

将 UPDATE 查询行更改为：

cursor.execute("UPDATE accounts SET Q001 = %s, Q002 = %s WHERE id = %s", 
               (Q001, Q002, session['id'],))

...你应该回到正轨。

Python Flask MySQL，UPDATE 查询有问题

Python Flask MySQL, problem with UPDATE query

python

mysql

flask

cgi