insert data into database using ajax, javascript and php

Question

The problem is: My motive is to get the subject name from the admin and insert it into database. Then i want to give the result of my query onto the same web page without refreshing it as the ajax should do. The following code is giving wrong o/p. I tried many syntaxes but still wrong response from the code. Please tell me the correct way.

My HTML code is:

<form>
    <input type="text" name="subject" />
    <div id="subject"></div>
    <input type="button" value="Submit" onclick="addSubject()" />
    <script src="home.js">
    </script>
</form>

My home.js code is:

function addSubject() {
    a=document.getElementsByName("subject")[0].value;
    destination="ajaxstoresubject.php?a:"+a+";";
    var xhr=new XMLHttpRequest();
    xhr.open("GET",destination,true);
    xhr.send();
    xhr.onreadystatechange=function() {
        if(xhr.readyState==4 && xhr.status==200) {
            document.getElementById("Subject").innerHTML=xhr.responseText;
        }
    }
}

ajaxstoresubject.php's code is:

<?php
$subject=$_GET["a"];
$con=mysqli_connect("localhost","root","","doortolearn");
if(!$con){
    echo("No database connection.");
}
$query="insert into subjects(sid) values('$subject')";
$result=mysqli_query($con,$query);
if($result){
    echo("Subject successfully inserted");
}
else{
    echo("Subject could not be inserted. Might be, the subject already exists.");
}
?>

The problem is: It inserts an empty value into the sid column of subject table. I checked, sid is varchar still the problem. It is also not giving any output on the web Page.

Please don't suggest JQUERY. I don't know anything about that.

Presumably any suggestion we make is going to be something 'you don't know about' - otherwise you wouldn't have asked! — Strawberry, Jun 08 '14 at 11:16
Please solve my this problem, you may vote it -100. I m too barehanded to solve this problem from last five days. :( @Strawberry I shall remember you throughout my life. — Rahul Goel, Jun 08 '14 at 11:19
**Danger**: You are **vulnerable to [SQL injection attacks](http://bobby-tables.com/)** that you need to [defend](http://stackoverflow.com/questions/60174/best-way-to-prevent-sql-injection-in-php) yourself from. — Quentin, Jun 08 '14 at 11:29
I m not covering SQL injections. :( Please solve the exact problem except of voting negative :( @Quentin — Rahul Goel, Jun 08 '14 at 11:32
@RahulGoel — Moaning when people look at your code, decide that they don't have the time to debug it, but helpfully point out a serious security problem is not a good way to endear yourself to the community. — Quentin, Jun 08 '14 at 14:44

score 1 · Answer 1 · answered Jun 08 '14 at 11:24

1

Check the correct format for GET query string. Try changing destination="ajaxstoresubject.php?a:"+a+";"; to destination="ajaxstoresubject.php?a="+a;

answered Jun 08 '14 at 11:24

Dariusz

371
1
9

Thank you for the answer but it is still the same. Please give me other answer. I think you can solve this problem – Rahul Goel Jun 08 '14 at 11:29

score -2 · Answer 2 · edited Jun 20 '20 at 09:12

Its All works fine here just now I checked your code every thing works fine.

Most importantly Try to work with XAMPP server because some times I also download free projects and when I try to run that project using WAMP server, its not working, but XAMPP start the in real quick way, WAMP always want updates, but I will not perfer to you work with WAMP on local server...

Start work with XAMPP its really nice and user friendly too.
Decalre your datastring properly just now I noticed your datastring not declared properly it should be decalre like this:
```
 destination="ajaxstoresubject.php? a="+a;
```
I also run this code on my local server and its work perfectly with JavaScript, just concentrate on your double quotes, commas, camel letters while declaring...

insert data into database using ajax, javascript and php

2 Answers2