Ajax不起作用-已发布修复PHP

Html:

php:

标题'Content-Type:application/json'

<?php

error_reporting(E_ALL);
ini_set('display_errors', 1);

$alert1 = null;
$uname = filter_input(INPUT_POST, isset($_POST['uname'])); 

if ($uname === $_POST['uname'] ? $_POST['uname'] : ''){
try {
$conn = new PDO('mysql:host=127.0.0.1;dbname=users', 'root', 'redcardinal');
$conn->setAttribute(PDO::ATTR_EMULATE_PREPARES, false);
$conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
$query = 'SELECT * FROM `usernames` WHERE `uname` = :uname';
$stmt = $conn->prepare($query);
$stmt->bindParam(":uname",$uname, PDO::PARAM_STR, strlen($uname));



$stmt->execute();
$hello = array(array());
if ($hello = $stmt->fetch(PDO::FETCH_ASSOC) ? $hello != null : ''){
    $alert1 = "This name is taken.";
echo json_encode($alert1);
$conn = null;
$query = null;
}
elseif ($hello === null) {
    $alert2 = "This name is not taken.";
 echo json_encode($alert2);
}

}
catch (PDOException $e) { echo json_encode($e);
$conn = null;
$query = null;

}

EDIT: WILL PUT ADDITIONAL elseif HERE.

}
?>

<?php 

标题'Content-Type:application/json'

<?php

error_reporting(E_ALL);
ini_set('display_errors', 1);

$alert1 = null;
$uname = filter_input(INPUT_POST, isset($_POST['uname'])); 

if ($uname === $_POST['uname'] ? $_POST['uname'] : ''){
try {
$conn = new PDO('mysql:host=127.0.0.1;dbname=users', 'root', 'redcardinal');
$conn->setAttribute(PDO::ATTR_EMULATE_PREPARES, false);
$conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
$query = 'SELECT * FROM `usernames` WHERE `uname` = :uname';
$stmt = $conn->prepare($query);
$stmt->bindParam(":uname",$uname, PDO::PARAM_STR, strlen($uname));



$stmt->execute();
$hello = array(array());
if ($hello = $stmt->fetch(PDO::FETCH_ASSOC) ? $hello != null : ''){
    $alert1 = "This name is taken.";
echo json_encode($alert1);
$conn = null;
$query = null;
}
elseif ($hello === null) {
    $alert2 = "This name is not taken.";
 echo json_encode($alert2);
}

}
catch (PDOException $e) { echo json_encode($e);
$conn = null;
$query = null;

}

EDIT: WILL PUT ADDITIONAL elseif HERE.

}
?>

<?php 

我基本上按照建议更改了PHP，我能想到的唯一其他问题是html或ajax。谢谢你的if$hello=null{

您需要将其更改为if$hello==null{

关于第二个问题，有两件事是错误的

将if$uname！=null&&$alert1=null{更改为if$uname！=null&&$alert1==null{您需要使三个===代替1=

再次将else$alert1！=null{更改为elseif$alert1！=null{您需要执行另一个if语句，因此需要执行esleif而不是else

错误报告全部； ini设置“显示错误”，1； 包括“check_name.php”

$uname=filter_inputINPUT_POST，isset$_POST['uname']

如果$uname！=null&&$alert1===null{ 试一试{ $conn=new-PDO'mysql:host=127.0.0.1；dbname=users'，'root'，'password'； $conn->setAttributePDO:：ATTR\u EMULATE\u PREPARES，false； $conn->setAttributePDO:：ATTR_ERRMODE，PDO:：ERRMODE_异常

$uname=$_POST['uname']

$upassword=password\u hash$\u POST['upassword']，密码\u默认值

$stmt='插入用户名uname，upassword值：uname，：upassword'； $query=$conn->prepare$stmt； $query->bindParam:uname，$uname，PDO:：PARAM_STR，strlen$uname； $query->bindParam:upassword，$upassword，PDO:：PARAM_STR，strlen$upassword

$query->execute； } 捕获$e{ 打印错误！：.$e->getMessage； 死亡 } } elseif$alert1！=null{

echo json_Encode此名称已使用，请选择其他名称。； }

$query=null； $conn=null

？>

---

如果$uname=isset$\u POST['uname']？isset$\u POST['uname']：{如果$uname=isset$\u POST['uname']？$\u POST['uname']，可能应该是：{为了给你$unameA中的$unameA中的$unameA的值，很多ifs都是赋值=而不是比较==。如果这不是故意的，我想你会因此产生一些错误。from：赋值表达式的值就是赋值。也就是说，$a=3的值是3。这允许你做一些比较cky的事情。有时我会意外地感谢你，我已经按照你的建议更改了代码，但现在我相信我的AJAX调用有问题。我也会发布。谢谢

error_reporting(E_ALL); 
ini_set('display_errors', 1); 
include 'check_name.php'; 

$uname = filter_input(INPUT_POST, isset($_POST['uname'])); 

if ($uname != null && $alert1 === null) { 
try {
$conn = new PDO  ('mysql:host=127.0.0.1;dbname=users', 'root', 'redcardinal'); 
$conn->setAttribute(PDO::ATTR_EMULATE_PREPARES, false); 
$conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION); 

$uname = $_POST['uname']; 

$upassword = password_hash(filter_input(INPUT_POST, isset($_POST['upassword'])), PASSWORD_DEFAULT); 



$stmt = 'INSERT INTO `usernames` (`uname`, `upassword`) VALUES (:uname,:upassword)'; 
$query = $conn->prepare($stmt); 
$query->bindParam(":uname",$uname, PDO::PARAM_STR, strlen($uname)); 
$query->bindParam(":upassword",$upassword, PDO::PARAM_STR, strlen($upassword)); 



$query->execute(); 
echo json_encode("Username/Password successfully created.");
} 
catch (PDOException $e) {
print "Error!: " . $e->getMessage() . "<br/>";
die();
}
}
elseif ($alert1 != null) { 

echo json_encode("Username/Password taken."); 
}

$query = null; 
$conn =null; 

<?php
header('Content-Type: application/json');


error_reporting(E_ALL);
ini_set('display_errors', 1);

$alert1 = null;

if ($uname = isset($_POST['uname']) ? isset($_POST['uname']) : ''){
try {
$conn = new PDO('mysql:host=127.0.0.1;dbname=users', 'root', 'password');
$conn->setAttribute(PDO::ATTR_EMULATE_PREPARES, false);
$conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
$query = 'SELECT * FROM `usernames` WHERE `uname` = :uname';
$stmt = $conn->prepare($query);
$stmt->bindParam(":uname",$uname, PDO::PARAM_STR, strlen($uname));



$stmt->execute();
$hello = array(array());
if ($hello = $stmt->fetch(PDO::FETCH_ASSOC) && $hello != null){
    $alert1 = "This name is taken.";
echo json_encode($alert1);
$conn = null;
$query = null;
}
if ($hello === null) {
    $alert1 = "This name is not taken.";
 echo json_encode($alert1);
}

}
catch (PDOException $e) { echo json_encode($e);
$conn = null;
$query = null;
$alert1 = null;
}



 }