PHP: How to excute query without form postback? - php

Question

I have a form in which i want to do the validations. But there is a field which i want to validate writing a query. I dont want the form to postback because after postback all the values filled in the form are lost. Is there any way i can write a query without postback or if i have to postback how to retain the values ? Please help

Answer 1

If you use AJAX (jQuery), you can post an XML Request without refreshing the browser, if this is what you need.
For this, just create a form with some textfields and a submit button, give everything an ID and add an click-Listener for the button:
$('#submit-button').click(function() {
var name = $('#username').val();
$.ajax({
type: 'POST',
url: 'php_file_to_execute.php',
data: {username: name},
success: function(data) {
if(data == "1") {
document.write("Success");
} else {
document.write("Something went wrong");
}
}
});
});
If the user clicks on the button with the "submit-button"-ID, this function is called. Then you send the value of the textfield using POST to the php_file_to_execute.php. Inside this .php-File, you can validate the username and output theresult:
if($_POST['username'] != "Neha Raje") {
echo "0";
} else {
echo "1";
}
I hope that I could help you! :)

Answer 2

You might want to rephrase what you wrote, its a bit unclear. FYI I do it like this;
<form method="post">
Text 1: <input type="text" name="form[text1]" value="<?=$form["text1"]?>" size="5" /><br />
Text 2: <input type="text" name="form[text2]" value="<?=$form["text2"]?>" size="5" /><br />
<input type="submit" name="submit" value="Post Data" />
</form>
And when I am processing the data, it's like this;
<?php
if ($_POST["submit"]) {
$i = $_POST["form"];
if ($i["text1"] or ..... ) { $error = "Something is wrong."; }
if ($i["text2"] and ..... ) { $error = "Maybe right."; }
if (!$error) {
/*
* We should do something here, but if you don't want to return to the same
* form, you should definitely post a header() or something like that here.
*/
header ("Location: /"); exit;
}
//
}
if (!$_POST["form"] and !$_GET["id"]) {
} else {
$form = $_POST["form"];
}
?>
By this method, the values are not lost unless you set them to get lost.

Answer 3

Use jQuery's $.post() method as:
$('#my_submit_button').click(function(event){
event.preventDefault();
var username = $('#username').val();
$.post('validate.php', {username: username, my_submit_button: 1}, function(response){
console.log(response); //response contain either "true" or "false" bool value
});
});
In validate.php get the username from your form asynchronously as like this:
if(isset($_POST['my_submit_button']) && $_POST['my_submit_button'] == 1 && isset($_POST['username']) && $_POST['username'] != "") {
// now here you can check your validations with $_POST['username']
// after checking validations, return or echo appropriate boolean value like:
// if(some-condition) echo true;
// else echo false;
}
Note: Please consider knowing security-related vulnerabilities and other issues before using AJAX for executing database-altering scripts.