Getting data from PHP file using Ajax and JQuery

Question

Im trying to get data from my php file using success function(data)

When im using console.log(data) i get; true/false/exists But i cant make a if statement, if i do it dosent alert!!

Heres my js file

function ajaxCall(username, email, password){

$.ajax({
    type: 'POST',
    url: '../register.php',
    data:   {
        'username' : username,
        'email' : email,
        'password' : password,
    },
    success: function(data) {
     if(data === "exists")
     alert("user exists");
    }
});

}

heres my .php file

<?php

$servername = "#";
$username = "#";
$password = "#";
$dbname = "#";

$regusername = $_POST['username']; 
$email = $_POST['email']; 
$regpassword = $_POST['password'];   

$mysqli = new mysqli($servername, $username, $password, $dbname);
$selectQuery = "SELECT username FROM users WHERE username = '$regusername'";
$select = $mysqli->query($selectQuery);
// var_dump($select->num_rows);

if( $select->num_rows == 0) {
    $insertQuery = "INSERT INTO users (username, password, email) VALUES ('$regusername','$regpassword','$email');";
    $insert = $mysqli->query($insertQuery);

        if( $insert == true) {
            echo "true";
        }else {
            echo "false";
        }
}else {
    echo "exists";
}

?>

Thanks for the help guys, really appreciate it. ($.trim(data) did the job. But will use a more properly structured data format. Anyways, this was my first post on stackoverflow, and you guys who help people here are awesome. This will probably not be my last post here ;-) Thanks for now! — Jonas Alvarson
– Jonas Alvarson, Commented Oct 23, 2015 at 11:39

Steve · Accepted Answer · 2015-10-23 11:34:34Z

2

Use a properly structured data format, such as json:

php:

$data=['exists'=>false];
if( $select->num_rows == 0) {
    $insertQuery = "INSERT INTO users (username, password, email) VALUES ('$regusername','$regpassword','$email');";
    $data['inserted'] = (bool) $mysqli->query($insertQuery);
}else {
    $data['exists']=true;
}
header('Content-Type: application/json');
echo json_encode($data);
die();

JS

$.ajax({
    type: 'POST',
    url: '../register.php',
    data:   {
        'username' : username,
        'email' : email,
        'password' : password,
    },
    success: function(data) {
       if(data.exists){
           alert("user exists");
       }elseif(data.inserted){
           alert("inserted");
       }else{
           alert("did not insert");
       }
});

edited Oct 23, 2015 at 11:34

answered Oct 23, 2015 at 11:22

Steve

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3 Comments

Jonas Alvarson Over a year ago

@charlietfl answer worked! But should i rebuild my code like you did it?

Steve Over a year ago

@JonasAlvarson Thats entirely up to you - however if you ever want to send more than a single variable back to the javascript, then json is the way, so you might as well get into the habit.

charlietfl Over a year ago

@JonasAlvarson I would use the json. In the long run you will find it better as you may decide to add additional information later also and it is simple to add another property

charlietfl · Accepted Answer · 2015-10-23 11:09:48Z

1

Chances are there is extra whitespace in the response

Try:

if($.trim(data) === "exists")

answered Oct 23, 2015 at 11:09

charlietfl

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1 Comment

Jonas Alvarson Over a year ago

if($.trim(data) worked like a charm! But should i rebuild my code like @steve did?

Marcus · Accepted Answer · 2015-10-23 11:14:36Z

1

I think its better to work with HTTP-Status codes like 404 or 403 (https://en.wikipedia.org/wiki/List_of_HTTP_status_codes) instead of retuning a string. This can by done with PHP (http://php.net/manual/de/function.http-response-code.php) and use the error callback of your ajax call (http://api.jquery.com/jquery.ajax/ --> StatusCode)

answered Oct 23, 2015 at 11:14

Marcus

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Comments

MakeLoveNotWar · Accepted Answer · 2015-10-23 11:55:32Z

1

You are not responding with an answer to the front, you just echoing 'exist' word in your php handler. Try using json_encode, because the dataType is "json" by default not "html"

Lets's say

if($insert) { 
 $response['exist_status'] = 'exist' 
}else{ 
 $response['exist_status'] = 'do not exist' 
} 
echo json_encode($response);

In your jquery

success: function(response) { 
 if(response.exist_status && response.exist_status == 'exist')  { 
  alert(1); 
 } 
}

edited Oct 23, 2015 at 11:55

answered Oct 23, 2015 at 11:11

MakeLoveNotWar

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4 Comments

Jonas Alvarson Over a year ago

ah im sorry. yeah ill rewrite my code a bit. Thanks for the help. Really appreciate it!

Steve Over a year ago

You might want set an appropriate content type header, and use booleans instead of strings where appropriate. However +1 as this is still a better option than echoing a string

MakeLoveNotWar Over a year ago

Combine both answers and you will get what you need, don't forget the die() as Steve posted it in his answer...

Steve Over a year ago

@MancharyManchaary Just noticed you are not actually outputting the json - return does not work in this context, you need to echo or print the response. Please edit for future visitors

Meenesh Jain · Accepted Answer · 2015-10-25 08:15:31Z

-1

if(data == "exists") instead of  if(data === "exists")

edited Oct 25, 2015 at 8:15

Meenesh Jain

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answered Oct 23, 2015 at 11:08

Manya Birajdar

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5 Comments

Jonas Alvarson Over a year ago

Allready tried that.. it didnt do the job.. am i misssing something out? Like dataType: 'json',

Manya Birajdar Over a year ago

text will be default . you are not returning json data so no need to write json

Manya Birajdar Over a year ago

write console.debug(data); in success and debug in console.

Jonas Alvarson Over a year ago

if im using console.debug(data); i get "exists" even when im randomly typing in different user/email & passwords that i know dont exists in the database.

charlietfl Over a year ago

@JonasAlvarson also check length of data and it likely isn't 6 due to whitespace that you don't see

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