删除语句 php MySQL

Question

我的代码需要一些帮助，当我点击提交代码时，它总是显示 "User successfully kicked"。但是，查询没有执行成功，用户还在数据库中。

编辑：修复了 mysql/msqli 问题。查询现在回答 "Something went wrong" 而不是 "User successfully kicked"。但是我不会从 mysql_error 报告中得到任何错误。我能做什么？

include 'connect.php';

if(empty($_POST['user_id'])) 
    {
            echo '<form method="post" action="">
                  User_id: <input type="text" name="user_id" />
                 <input type="submit" value="Kick user" />
                 </form>';

    }
    else 
    {
        $sql = "DELETE FROM users
                WHERE 
                user_id = '" .mysqli_real_escape_string($_POST['user_id']) . "'
                ";

        $result = mysqli_query($con, $sql);
        if($result)
        {
            //something went wrong, display the error
            echo 'Something went wrong!.';
            echo mysqli_error(); //debugging purposes, uncomment when needed
        }
        else
        {
            echo 'User successfully kicked!';
        }
    }

我的 connect.php 看起来像这样：

<?php
$con=mysqli_connect ("localhost","root","","dps");
if (mysqli_connect_errno()) {
echo "failed to connect mysql: ". mysqli_connect_error();
}
?>

Answer 1

添加：

$result = mysqli_query($con, $sql);

之后：

$sql = "DELETE FROM 
                    users
                WHERE 
                    user_id = '" . mysql_real_escape_string($_POST['user_id']) . "'
                ";

Answer 2

您正在 if 部分设置 $sql 变量，并尝试在 else 部分访问它。这是行不通的。此外，您正在混合不好的库（mysql 与 mysqli 不同，请使用 mysqli 因为 mysql 已弃用并将被删除来自 php)

include 'connect.php';

if(empty($_POST['user_id'])) 
{
        echo '<form method="post" action="">
              User_id: <input type="text" name="user_id" />
             <input type="submit" value="Kick user" />
             </form>';

}
else 
{
    $sql = "DELETE FROM users
            WHERE 
            user_id = '" .mysqli_real_escape_string($con, $_POST['user_id']) . "'
            ";

    $result = mysqli_query($con, $sql);
    if(!$result)
    {
        //something went wrong, display the error
        echo 'Something went wrong!: ';
        echo mysqli_error($con) //debugging purposes, uncomment when needed
    }
    else
    {
        echo 'User succesfully kicked!';
        mysqli_free_result($result);
    }
}

您可能需要更改 connect.php 才能使用 mysqli

编辑：现在应该修复一些错误

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