how to get last inserted id after inserting using codeigniter and jquery - php

Question

Please help me on how to get the last inserted id from database using codeigniter and jquery. What I want is to get the the last inserted id after inserting. I am using jquery to insert the data. I don't have any idea on how to it. Thanks a lot in advance.
SCRIPT
$('#add-tag').click(function () {
var lang = $('#lang').val();
var tag = $('#tag').val();
var data = {
tag: tag,
lang: lang
}
if (tag === '') {
$('.error').html('<h4><i class="glyphicon glyphicon-info-sign">' +
'</i> Field cannot be empty!</h4>').addClass('bounceIn').show();
$('.error').delay(3000).fadeOut();
} else {
$.ajax({
url: "<?= site_url('blog/add_tag'); ?>",
type: 'POST',
data: data,
success: function (result) {
//display message if successful
$('.message').html('<h4><i class="glyphicon glyphicon-ok">' +
'</i> Tag has been added</h4>').addClass('bounceIn').show();
$('.message').delay(3000).fadeOut();
$('#tag').val('');
$('#tags').append('<a class="tags animated fadeInDown">' +
'<span class="remove-tag" id="remove-tag' + lid + '">' +
'</span></span> ' + tag + '</a>');
window.setTimeout(function () {
location.reload();
}, 2000);
}
});
}
});
VIEW
<div class="row">
<div class="col-md-12 col-sm-12 col-xs-12">
<div id="add-tag-form" class="display-none relative">
<div class="well well-sm">
<div class="row">
<div class="col-md-12 col-sm-12 col-xs-12">
<h5>Add Tag</h5>
<input type="text" id="tagLastID" class="form-control" placeholder="Tag Last ID" readonly>
<input type="hidden" id="lang" class="form-control" placeholder="Lang" required value="<?= $lang; ?>">
<input type="text" id="tag" class="form-control" placeholder="Tag" required>
<br />
<button id="add-tag" class="btn col-md-12 col-sm-12 col-xs-12">Add Tag</button>
<div class="text-center"><a id="close-tag">cancel</a></div>
</div>
</div>
</div>
</div>
<button id="add-tag-btn" class="btn col-md-12 col-sm-12 col-xs-12">Add Tag</button>
</div>
</div>
CONTROLLER
public function add_tag() {
$this->Mblog->addTag();
}
MODEL
public function addTag() {
$lang = $this->input->post('lang');
$tag = $this->input->post('tag');
$data = array(
'tags' => $tag,
'lang' => $lang
);
$this->blog->insert('tags', $data);
return $this->blog->insert_id();
}

Answer 1

Add return to your controller function or echo the result like as follows:
public function add_tag() {
return $this->Mblog->addTag();
}
OR
public function add_tag() {
echo json_encode(['data' => $this->Mblog->addTag()]);
exit;
}
And then try to modify dump and see the ajax success response:
$.ajax({
url: "<?= site_url('blog/add_tag'); ?>",
type: 'POST',
data: data,
dataType: 'json', // this will convert your results to json by default
success: function (result) {
// You should get the json result
console.log(result.data);
// Your regular logic to handle result
},
fail: function(res) {
console.log(res); // will log fail results
}
});
Try these and let us know if this works for you or not.

Answer 2

If you are asking that how to return data from controller to jQuery then yes, this is the answer.
Replace your controller code with this
public function add_tag() {
$insert_id = $this->Mblog->addTag();
echo(json_encode(array("insert_id"=>$insert_id)));
}
The echo'ed result will be appear in your success of jQuery.ajax.

Answer 3

You're already returning the id from the Model, so in your controller the only thing you have to do is echo-ing the result.
public function add_tag() {
echo $this->Mblog->addTag();
}
Then in you jquery the result will be what you have echoed from the controller.