Python 如何将数据插入SQlite数据库中的特定列中？

我有一个变量列表。我希望遍历列表中的每个元素，并将其添加到列的行中。但是，当我更新表并打开数据库时，列中没有显示任何内容（仅为null）

当我将列表添加到列中时，我的目标是对数据进行一些分析。我正在为学校做一个项目，其中一个组成部分是通过/不通过学生，并给他们相应的分数

我正在使用PythonIdle和SQlite数据库。 我尝试了遍历列表，并将每个值放入列的下一行。 我尝试了所有不同的语法（例如%s、（？）…）

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当我清除了语法消息，并且没有发现错误时，我检查了我的数据库，但那里什么都没有。

打印update语句以查看是否一切正常。将提交移到for循环之外。示例（MySql）

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补充答案

Python准备的sql使用“%s”作为变量，更改为问号。 所以

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应该是

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使用创建、插入、更新然后选择的PHP脚本。尝试一次更新一个，然后添加另一个，等等

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输入

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print语句似乎有效，结果如下：更新类集百分比=（？）其中第一个=（？）（99，1）更新类集百分比=（？）其中第一个=（？）（98，2）更新类集百分比=（？）其中第一个=（？）（97，3）更新类集百分比=（？）其中第一个=（？）（96，4）更新类集百分比=（？）其中第一个=（？）（76，5）更新类集百分比=（？）其中第一个=（？）（90，6）更新类集百分比=（？）其中第一个=（？）（78，7）但它仍然没有更新数据库。请确保数据库的用户ID具有更新权限。对于Mysql，命令是：SHOW GRANTS[对于用户]
        for i, val in enumerate (b):
            c.execute("UPDATE class SET percentage = (?) WHERE first = (?)",(val,(i+1)))
            conn.commit()

for i, val in enumerate (b):
    print("UPDATE class SET percentage = (?) WHERE first = (?)",(val,(i+1))
    c.execute("UPDATE class SET percentage = (?) WHERE first = (?)",(val,(i+1)))
    conn.commit() #move to outside for loop, call commit once

 c.execute("UPDATE class SET percentage = (?) WHERE first = (?)",(val,(i+1)))

 c.execute("UPDATE class SET percentage = (%s) WHERE first = (%s)",(val,(i+1)))

<?php
$servername = "";
$username = "";
$password = "";
$dbname = "";

// Create connection
$conn = new mysqli($servername, $username, $password, $dbname);
// Check connection
if ($conn->connect_error) {
    die("Connection failed: " . $conn->connect_error);
}

$sql[0] = "drop table classes;";
if ($conn->query($sql[0]) === TRUE) {
    echo "Script successful";
} else {
    echo "Error: " . $sql . "<br>" . $conn->error;
}

$sql[1] = "CREATE TABLE classes (class_no integer,percentage text,weekday text, date_percent date);";
if ($conn->query($sql[1]) === TRUE) {
    echo "Script successful";
} else {
    echo "Error: " . $sql . "<br>" . $conn->error;
}

$sql[2] = "INSERT INTO classes VALUES(1, '100', 'Tuesday', '2019-10-01' );";
if ($conn->query($sql[2]) === TRUE) {
    echo "Script successful";
} else {
    echo "Error: " . $sql . "<br>" . $conn->error;
}

$sql[3] = "INSERT INTO classes VALUES(2, '90', 'Wednesday', '2019-10-02' );";
if ($conn->query($sql[3]) === TRUE) {
    echo "Script successful";
} else {
    echo "Error: " . $sql . "<br>" . $conn->error;
}



$sql = "SELECT class_no, percentage, weekday FROM classes";
$result = $conn->query($sql);

if (mysqli_num_rows($result) > 0) {
    // output data of each row
    while($row = mysqli_fetch_assoc($result)) {
        echo "<br>Class No: " . $row["class_no"]. " Percentage: " . $row["percentage"]. " Weekday: " . $row["weekday"]."    <br><br>";
    }
} else {

    echo "0 results";
}


$sql_u = "Update classes set percentage = '100' where class_no = 2;";
if ($conn->query($sql_u) === TRUE) {
    echo "Script update successful";
} else {
    echo "Error: " . $sql . "<br>" . $conn->error;
}


$sql = "";
$sql = "SELECT class_no, percentage, weekday FROM classes";
$result = $conn->query($sql);

if (mysqli_num_rows($result) > 0) {
    // output data of each row
    while($row = mysqli_fetch_assoc($result)) {
        echo "<br>Class No: " . $row["class_no"]. " Percentage: " . $row["percentage"]. " Weekday: " . $row["weekday"]."    <br><br>";
    }
} else {

    echo "0 results";
}
$conn->close();
?>

output:

Script successfulScript successfulScript successfulScript successful
Class No: 1 Percentage: 100 Weekday: Tuesday 


Class No: 2 Percentage: 90 Weekday: Wednesday 

Script update successful
Class No: 1 Percentage: 100 Weekday: Tuesday 


Class No: 2 Percentage: 100 Weekday: Wednesday