Check if record exists in mySQL Database on blur - php

Question

I am thinking on how to implement this scenario:
I have a table orders where there is a serialNumber field. Then I also a have a PHP page with a form. What I am thinking of doing is that, onBlur or on keypress enter/return of a <input type=text> field, I would like an ajax/jquery script to check the serial number from the text box input if it has an existing record in my mySQL database. Then the script will warn the user that the serial number exists already in the database and will not allow submission.
I know how to implement it with standard form submission but I was thinking is it can be done without the literal pressing of the submit button.
Is there a way to implement this?

Answer 1

for this you can use javascript. create on javascript that called on textbox on blur event.
here i created on function that called on textbox on blur event.
function CheckUserName(){
var UserName = document.getElementById('UserName');
if(UserName.value != "")
{
if (window.XMLHttpRequest)
{// code for IE7+, Firefox, Chrome, Opera, Safari
xmlhttp=new XMLHttpRequest();
}
else
{// code for IE6, IE5
xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
}
xmlhttp.onreadystatechange=function()
{
if (xmlhttp.readyState==4 && xmlhttp.status==200)
{
var value = xmlhttp.responseText;
if(value.length > 1)
{
document.getElementById('ErrorSpan').innerHTML="User Name Already exist please choose Other User Name";
UserName.focus();
}
else
{
document.getElementById('ErrorSpan').innerHTML="";
}
}
}
xmlhttp.open("GET","checkUserName.php?q="+UserName.value,true);
xmlhttp.send();
}
}
and create one php file with the name checkusername.php and pass your value through query string.
php code as follow.
<?php
$q=$_GET["q"];
include("db_connect.php");
$sql="select * from usermaster where UserName='".$q."'";
$result = mysql_query($sql);
while($row = mysql_fetch_array($result))
{
echo $row['UserName'];
}
mysql_close($con);
?>
here from php if username find it will return value and you can get value in your javascript function. i hope it will help you.

Answer 2

you can also use this method I checked it on keyup you can use it via onblur option.
<input type="text" value="" id="jform_domain_name" name="jform[domain_name]" onkeyup="checkAvailability();"/>
<div id="errormsg" class="no-display">Sorry, this name is not available!</div>
<div id="successmsg" class="no-display">Congratulations, this domain is available!</div>
<script>
function checkAvailability(){
jQuery('#ajaxloader').html('<img src="images/ajax-loader.gif" />');
var string = jQuery('#jform_domain_name').val();
if(string == ''){
jQuery('#ajaxloader').html('');
return false;
}
jQuery.ajax({
type : "POST"
,url : "YOUR_ACTION_URL"
,data :"string="+jQuery('#jform_domain_name').val()
,success : function(data){
if(data==0){
var errormsg = jQuery("#errormsg").html();
jQuery("#ajaxloader").show();
jQuery('#ajaxloader').html(errormsg);
}else{
var successmsg = jQuery("#successmsg").html();
jQuery("#ajaxloader").show();
jQuery('#ajaxloader').html(successmsg);
}
}
,complete : function(){
if( jQuery('#jform_domain_name').val() == "" ) {
jQuery("#ajaxloader").hide();
}
}
,beforeSend: function(html){
jQuery("#ajaxloader").show();
jQuery('#ajaxloader').html('<img style="padding-top:6px;" src="images/ajax-loader.gif" />');
return;
}
});
}
</script>
for reference I am providing my controller action and the model which I have used
//sample controller action
function checkdomain(){
$requestData = JRequest::get();
$return = $model->checkAvailabiLity($requestData['string']);
if($return === false){
echo 0;
}else{
echo 1;
}
die;
}
//sample model on which I created Query logic.
public function checkAvailabiLity($data){
$select = "SELECT id FROM #__jshopping_vendors WHERE domain_name = '".strtolower($data)."' AND user_id != ".$user->id."";
$db->setQuery($select);
$type = $db->loadObject();
if(isset($type->id) && $type->id >0){
return false;
}else{
return true;
}
}
hope this helps....