Three days had passed and still having problems to get this things work. This AJAX Call on my js file seems working when it comes to sending JSON data:
var _lname = $['#ptLastName'].val[];
var _fname = $['#ptFirstName'].val[];
var _mname = $['#ptMiddleName'].val[];
var _gender = $['#ptGender'].val[];
var _bday = $['input[name="birthdate"]'].val[]; // $['#ptBirthDate'].val[];
var _ssn = $['#ptSSN'].val[];
$.ajax[{
type: "POST",
url: ".././CheckPerson.php",
data: "{'lastName':'" + _lname + "','firstName':'" + _fname + "','middleName':'" + _mname + "'}",
contentType: "application/json; charset=utf-8",
dataType: "json",
success: function [response] {
var res = response.d;
if [res == true] {
jAlert['Person Name already exists!', 'Error'];
return;
}
}]
but in my PHP file:
$lastname = json_decode[$_POST['lastName']];
$firstname = json_decode[$_POST['firstName']];
$middlename = json_decode[$_POST['middleName']];
$response = array[];
mysql_connect ["*****", "****"] or die ['Error: ' . mysql_error[]];
mysql_select_db ["********"];
$query = "SELECT Lastname, Firstname, MiddleName FROM tbl_people WHERE Lastname = '$lastname' || Firstname = '$firstname' || MiddleName = '$middlename'";
$result = mysql_query[$query];
$row = mysql_fetch_array[$result];
if [$row] {
$response = json_encode[array['d' => true, 'test' => $lastname]];
}
else {
$response = json_encode[array['d' => false, 'test' => $lastname]];
}
echo $response;
print json_encode[$_POST];
some error from firebug console says:
Notice: Undefined index: lastName in C:\xampp\htdocs\..\CheckPerson.php on line 2
Notice: Undefined index: firstName in C:\xampp\htdocs\..\CheckPerson.php on line 3
Notice: Undefined index: middleName in C:\xampp\htdocs\..\CheckPerson.php on line 4
{"d":false,"test":null}[]
i believe that json_decode[]
is working fine in my php file but $_POST['']
can't recognize my posted data from my ajax call w/c variables had been declared:
data: "{'lastName':'" + _lname + "','firstName':'" + _fname + "','middleName':'" + _mname + "'}",
I believe I am doing right with my codes seems i had read many questions here and done what they had said but don't know why the error occurred. Is there any problem/bug you had seen? please tell me.
AJAX can be used for interactive communication with a database.
AJAX Database Example
The following example will demonstrate how a web page can fetch information from a database with AJAX:
Example
Person info will be listed here...
Example Explained - The MySQL Database
The database table we use in the example above looks like this:
1 | Peter | Griffin | 41 | Quahog | Brewery |
2 | Lois | Griffin | 40 | Newport | Piano Teacher |
3 | Joseph | Swanson | 39 | Quahog | Police Officer |
4 | Glenn | Quagmire | 41 | Quahog | Pilot |
Example Explained
In the example above, when a user selects a person in the dropdown list above, a function called "showUser[]" is executed.
The function is triggered by the onchange event.
Here is the HTML code:
Example
function showUser[str] {
if [str == ""] {
document.getElementById["txtHint"].innerHTML = "";
return;
} else {
var xmlhttp = new XMLHttpRequest[];
xmlhttp.onreadystatechange = function[] {
if [this.readyState == 4 && this.status == 200] {
document.getElementById["txtHint"].innerHTML = this.responseText;
}
};
xmlhttp.open["GET","getuser.php?q="+str,true];
xmlhttp.send[];
}
}
Select a person:
Peter Griffin
Lois Griffin
Joseph Swanson
Glenn Quagmire
Run example »
Code explanation:
First, check if person is selected. If no person is selected [str == ""], clear the content of txtHint and exit the function. If a person is selected, do the following:
- Create an XMLHttpRequest object
- Create the function to be executed when the server response is ready
- Send the request off to a file on the server
- Notice that a parameter [q] is added to the URL [with the content of the dropdown list]
The PHP File
The page on the server called by the JavaScript above is a PHP file called "getuser.php".
The source code in "getuser.php" runs a query against a MySQL database, and returns the result in an HTML table:
table {
width: 100%;
border-collapse: collapse;
}
table, td, th {
border: 1px solid black;
padding: 5px;
}
th {text-align: left;}
Explanation: When the query is sent from the JavaScript to the PHP file, the following happens:
- PHP opens a connection to a MySQL server
- The correct person is found
- An HTML table is created, filled with data, and sent back to the "txtHint" placeholder