单击保存按钮时，如何使用PHP将文本区域中的文本保存到MySQL数据库中？

我有一个HTML文本区，登录用户可以在其中输入和保存注释。我使用以下脚本从数据库中检索保存的注释

<?php
function notes() {
    $password = "fake_password";
    $connect = mysql_connect("localhost", "user", $password) or die("Couldn't connect to the database!");
    mysql_select_db("db_name") or die("Couldn't find the database!");

    $query = mysql_query("SELECT * FROM users WHERE notes!=''");
    $numrows = mysql_num_rows($query);

    if ($numrows != 0) {
        while ($row = mysql_fetch_assoc($query)){
            $notes = $row['notes'];
        }

        echo $notes;
    }
}
?>

---

首先：应该使用连接数据库，而不是mysql，并且易于在web应用程序中使用，因此不安全

有了这个警告，我将使用mysql进行回复，因为您正在使用mysql

这不太难。当然，如果没有表结构或表单中的代码，下面必须使用示例字段名，并假设您将用户id存储在
$\u会话
变量中：

<?php
    function savenotes() {
        // The database connection code should be moved to a central function/location rather than called in every function
        $password = "fake_password";
        $connect = mysql_connect("localhost", "user", $password) or die("Couldn't connect to the database!");
        mysql_select_db("db_name") or die("Couldn't find the database!");

        // Retreive notes from form
        $notes = $_POST['notes']; // Assumes field is called notes, and you used method=POST
        // Assuming a user can only update their own notes, and that you are storing the user id somewhere
        $userid = $_SESSION['userid']; 
        $query = mysql_query("UPDATE users SET notes ='" . mysql_real_escape_string($notes) . "' WHERE userid = " . (int)$userid);


}

这是非常广泛的。开始阅读，然后是“我们几乎没有足够的信息来给出任何具体的答案”——您的表单发布到PHP，退出输入，然后执行
UPDATE
语句（或
INSERT
用于新行。textarea上没有
name=
属性，这意味着在提交表单时无法从
$\u POST
变量获取该属性。此外，您如何/在何处跟踪用户id？
<?php
    function savenotes() {
        // The database connection code should be moved to a central function/location rather than called in every function
        $password = "fake_password";
        $connect = mysql_connect("localhost", "user", $password) or die("Couldn't connect to the database!");
        mysql_select_db("db_name") or die("Couldn't find the database!");

        // Retreive notes from form
        $notes = $_POST['notes']; // Assumes field is called notes, and you used method=POST
        // Assuming a user can only update their own notes, and that you are storing the user id somewhere
        $userid = $_SESSION['userid']; 
        $query = mysql_query("UPDATE users SET notes ='" . mysql_real_escape_string($notes) . "' WHERE userid = " . (int)$userid);


}