Question

第16行的未定义变量（名称，电子邮件，浏览器，添加）....错误即将来临.....请帮助我删除错误这是我的代码

<?php

$con = mysqli_connect('localhost','root','');
if(!$con) { 
    echo 'not connected to database';
}
if(!mysqli_select_db($con,'student')) {
    echo 'database not selected';
}
if (isset($_POST['name'])){$name = $_POST['name'];}
if (isset($_POST['email'])){$email= $_POST['email'];}
if (isset($_POST['address'])){$add = $_POST['address'];}
if (isset($_POST['admission'])){$adm = $_POST['admission'];}

/*line:16*/                                                                        
$sql = "INSERT INTO student_record (name,email,address,joining_date) VALUES('$name','$email','$add','$adm')";
if ( !mysqli_query($con,$sql)) {
    echo 'not inserted';
} else {
    echo'inserted';
}

?>

Answer 1

这是因为您没有在if条件之前初始化变量。如果未找到POST数据，则未设置所有4个变量，则出现错误。 Plz试试这个

if($_POST){
    $con = mysqli_connect('localhost','root','');
    if(!$con)
    { 
        echo 'not connected to database';
    }
    if(!mysqli_select_db($con,'student'))
    {
        echo 'database not selected';
    }

    $error  =   true;
    $errorMessage   =   '';
    if (empty($_POST['name']) || empty($_POST['email']) || empty($_POST['address']) || empty($_POST['admission'])){
        $error  =   false;
        if(empty($_POST['name'])){
            $errorMessage   =   'Please enter name <br/>';
        }
        if(empty($_POST['email'])){
            $errorMessage   .=  'Please enter email <br/>';
        }
        if(empty($_POST['address'])){
            $errorMessage   .=  'Please enter address <br/>';
        }
        if(empty($_POST['admission'])){
            $errorMessage   .=  'Please enter admission <br/>';
        }
    }
    if($error){
        $name   = mysql_real_escape_string($_POST['name']);
        $email  = mysql_real_escape_string($_POST['email']);
        $add    = mysql_real_escape_string($_POST['address']);
        $adm    = mysql_real_escape_string($_POST['admission']);

        /*line:16*/                                                                        
        $sql = "INSERT INTO student_record (name,email,address,joining_date) VALUES('$name','$email','$add','$adm')";
        if ( !mysqli_query($con,$sql))
        {
            echo 'not inserted';
        }else{
            echo'inserted';
        }
    }else{
        echo $errorMessage;
    }
}

Answer 2

我认为您没有收到任何帖子数据。只需在执行之前添加if条件

if($_POST){  /*Do stuff check for the post['name'] run your SQL query */

由于帖子未定义，因此POST['name']未设置，并且它不会进入if块而仍未设置。

php中的未定义变量（错误）

2 个答案: