Check if username exists in database with codeigniter and ajax

Question

Can anyone help me check if a username is in my database using ajax and code igniter? I can't use the form_validation method as I have modal windows which interfere with the checking.

Currently my controller looks like:

 function filename_exists(){
        $username = $this->input->post('username');
        $data['exists'] = $this->User_model->filename_exists($username);
    }

My Model:

 function filename_exists($username)
 {

     $this->db->select('*'); 
     $this->db->from('users');
     $this->db->where('username', $username);
     $query = $this->db->get();
     if ($query->num_rows() == 0) {
         return true;
     } else {
         return false;
     }
 }

and my ajax post:

function check_if_exists() {

     <?php $username = $this->input->post('username');
    ?>
     var username = '<?php echo $username ?>';
    var DataString=$("#form1").serialize();
     $.ajax({
     url: "<?php echo base_url(); ?>index.php/Files/filename_exists/",
     type: "post",
     data: DataString + '&username=' + username,
     success: function(response) {


            if (response == true) {
                $('#msg').html('<span style="color: green;">'+msg+"</span>");

            }
             else {

                $('#msg').html('<span style="color:red;">Value does not exist</span>');
            }


         }
     });


}

UPDATE

 <form name = "form1" id = "form1" method ="post"> <!--action="<?php echo base_url()."index.php/Admin/create_user"; ?>"-->
    <?php echo validation_errors(); ?>
    <label for="userID" class = "labelForm">User ID:</label>
    <input type="text" id="userID" name="userID" class = "input2">
    <label for="first_name" class = "labelForm">First Name:</label>
    <input type="text" id="first_name" name="first_name" class = "input2">
    <label for="last_name" class = "labelForm">Last Name:</label>
    <input type="text" id="last_name" name="last_name" class = "input2">
    <label for="username" class = "labelForm">Username:</label>
    <input type="text" id="username" name="username" class = "input2" onblur="check_if_exists();">
    <label for="password" class = "labelForm">Password:</label>
    <input type="password" id="password" name="password" class = "input2" onblur="checkPasswords();">
    <label for="passconf" class = "labelForm">Password:</label>
    <input type="password" id="passconf" name="passconf" class = "input2" onblur="checkPasswords();">
    <label for="email" class = "labelForm">Email:</label>
    <input type="text" id="email" name="email" class = "input2">
  <button type="button"  id = "new_user_submit">Add New User</button>

change $query->num_rows() == 0 as $query->num_rows() > 0 and test — Rejoanul Alam
– Rejoanul Alam, Commented Jun 23, 2016 at 14:34
@Abdulla When i try to print the username nothing comes up , but if i console.log(DataString) in the success part of the ajax post it tells me what I have entered? — user
– user, Commented Jun 23, 2016 at 15:25

Abdulla Nilam · Accepted Answer · 2016-06-24 10:32:08Z

3

Try this

In Ajax

function check_if_exists() {

var username = $("#username").val();

$.ajax(
    {
        type:"post",
        url: "<?php echo base_url(); ?>index.php/files/filename_exists",
        data:{ username:username},
        success:function(response)
        {
            if (response == true) 
            {
                $('#msg').html('<span style="color: green;">'+msg+"</span>");
            }
            else 
            {
                $('#msg').html('<span style="color:red;">Value does not exist</span>');
            }  
        }
    });
}

In Controller

function filename_exists()
{
    $username = $this->input->post('username');
    $exists = $this->User_model->filename_exists($username);

    $count = count($exists);
    // echo $count 

    if (empty($count)) {
        return true;
    } else {
        return false;
    }
}

In Model

function filename_exists($username)
{
    $this->db->select('*'); 
    $this->db->from('users');
    $this->db->where('username', $username);
    $query = $this->db->get();
    $result = $query->result_array();
    return $result
}

edited Jun 24, 2016 at 10:32

answered Jun 23, 2016 at 16:39

Abdulla Nilam

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7 Comments

user Over a year ago

Unfortunately its still not working @Abdulla .. when I console.log(username) I can see the init , but when I write console.log(response) it comes up blank

user Over a year ago

I've actually found when I echo($count) in the controller it appears to work ( as in have it just before the if statement). This seems like strange behaviour though as when I take it out it seems to return false regardless of the username existing or not.. Is this okay to use like this? @abdulla really appreciate the help as well!

DevNinjaJeremy Over a year ago

Why query the db for all the users data? Here would be a better query that will take less time. `function filename_exists($username) { $this->db->where('username',$username); return $this->db->count_all_results('users'); }

always-a-learner Over a year ago

@AbdullaNilam Sir I get blank response in alert what should i do?

Abdulla Nilam Over a year ago

In controller instead of return add echo. Ex: return true should be echo true.

|

DevNinjaJeremy · Accepted Answer · 2016-07-12 14:31:02Z

2

If you are just trying to see if the user already exists, there is no reason to query with the get() function. just do the count_all_results() it will return a number if the user is found, 0 if not.

function filename_exists($username) {
  $this->db->where('username', $username);
  return $this->db->count_all_results('users'); 
}

All this will do is return a number greater than zero if the username exists in your db.

answered Jul 12, 2016 at 14:31

DevNinjaJeremy

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Comments

josevoid · Accepted Answer · 2016-06-24 10:50:26Z

Just another approach with same result

MODEL

function filename_exists($username) {
   $this->db->select()->from('users')->where('username', $username);
   $query = $this->db->get();

   return $query->first_row('array'); // returns first row if has record in db
}

CONTROLLER

function filename_exists() {
   $username = $this->input->post('username');
   $user = $this->user_modal->filename_exists($username);

   return !empty($user); // not empty returns true else false
}

AJAX

Inside the check_if_exists function.

$.post('<?php echo base_url(); ?>index.php/files/filename_exists', { username: $('#username').val() }, function(response) {
    var html = '<span style="color:red;">Value does not exist</span>';
    if (response == true) {
       html = '<span style="color: green;">' + msg + '</span>';
    } 
    $('#msg').html(html);
});

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