如何从html表单';将下拉列表放入mysql数据库?

如何从html表单';将下拉列表放入mysql数据库?,mysql,database,forms,select,html.dropdownlistfor,Mysql,Database,Forms,Select,Html.dropdownlistfor,有一个带有下拉列表的表单,其中第一个选项由defualt选择。如何将用户选择的值输入我的数据库?提前谢谢你的帮助 HTML表单下拉列表: <select name="extrafield5"> <option value="NOW" selected="selected">Submit order now</option> <option value="REVIEW">Submit my order for review</option&

有一个带有下拉列表的表单,其中第一个选项由defualt选择。如何将用户选择的值输入我的数据库?提前谢谢你的帮助

HTML表单下拉列表:

<select name="extrafield5">
 <option value="NOW" selected="selected">Submit order now</option>
 <option value="REVIEW">Submit my order for review</option>

</select>

下面是一个具有类似需求的示例段(PHP MySQL):

filename.php

<?php
    $servername = "localhost";
    $username = "root";
    $password = "";
    $tablename = "name_of_table";
    $db_name = "db_name";

    // Create connection
    $conn = new mysqli($servername, $username, $password);

    // Check connection
    if ($conn->connect_error) {
        die("Connection failed: " . $conn->connect_error);
   }

    if (isset($_POST['extrafield5'])){
        $extrafield5 = $_POST['extrafield5'];
    }
    else {$extrafield5 = '';}
    $sql = "INSERT INTO $tablename (fieldname) VALUES('$extrafield5');";
    mysql_select_db($db_name);
    $retval = mysql_query( $sql, $conn );
    if(! $retval )
    {
      die('Could not enter data: ' . mysql_error());
    }
    echo "Entered data successfully\n";
    mysql_close($conn);
?>
<!DOCTYPE html>
<html>
<head>
<title>PhpFiddle Initial Code</title>

<script type="text/javascript">
    /* Your scrips here */
</script>

<style type="text/css">
    /* Your css here */
</style>

</head>

<body>

<div style="margin: 30px 10%;">
    <h3>My form</h3>
    <form action="" method="post" id="myform" name="myform">
        <select name="extrafield5">
         <option value="NOW" selected="selected">Submit order now</option>
         <option value="REVIEW">Submit my order for review</option>
        </select>
        <input type="submit">
    </form>
</div>

</body>
</html>

是否要将来自数据库的值填充到下拉列表中?不,我正在尝试获取用户提交表单后选择的选项的值。因此
$\u POST['extrafield4']
是一个提交按钮吗?抱歉,这是一个输入错误。我无法将其用于下拉列表
<?php
    $servername = "localhost";
    $username = "root";
    $password = "";
    $tablename = "name_of_table";
    $db_name = "db_name";

    // Create connection
    $conn = new mysqli($servername, $username, $password);

    // Check connection
    if ($conn->connect_error) {
        die("Connection failed: " . $conn->connect_error);
   }

    if (isset($_POST['extrafield5'])){
        $extrafield5 = $_POST['extrafield5'];
    }
    else {$extrafield5 = '';}
    $sql = "INSERT INTO $tablename (fieldname) VALUES('$extrafield5');";
    mysql_select_db($db_name);
    $retval = mysql_query( $sql, $conn );
    if(! $retval )
    {
      die('Could not enter data: ' . mysql_error());
    }
    echo "Entered data successfully\n";
    mysql_close($conn);
?>
<!DOCTYPE html>
<html>
<head>
<title>PhpFiddle Initial Code</title>

<script type="text/javascript">
    /* Your scrips here */
</script>

<style type="text/css">
    /* Your css here */
</style>

</head>

<body>

<div style="margin: 30px 10%;">
    <h3>My form</h3>
    <form action="" method="post" id="myform" name="myform">
        <select name="extrafield5">
         <option value="NOW" selected="selected">Submit order now</option>
         <option value="REVIEW">Submit my order for review</option>
        </select>
        <input type="submit">
    </form>
</div>

</body>
</html>