Fetch Only new Entries Database mysql [closed] - php

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i need some little help .. i wanna fetch only new entry in my database without refresh my page..
ii have an php page which can display all record's of my database .. like someone entered new data in database i want to fetch only single entery .. don't fetch all entries of again .. i also read too many of articles about JSON ajax etc .. but no onehelps me about fetch only single entery . is here any way using xml or something's special to do this .. i don't have any idea how i can do it
thank you

Answer 1

A very general approach would be something like that:
On every page load run a script that checks every a certain time interval the database for new entries:
Javascript:
<script>
$(document).ready(function(){
setInterval(function(){
$.ajax({
type: 'POST',
url: 'ajaxfile.php'
}).success(function(response){
var response = $.parseJSON(response);
var username = response.username; //here we put hypothetical db column "username" in a variable
alert(username); //here we alert the "username" variable in order to verify the script. All other db columns can be called as: response.db_column_name
});
}, 10000); //interval time: 10000 milliseconds (10 seconds)
});
</script>
This script, combined with the following "ajaxfile.php" will display all database columns as: response.db_column
Before I give you my idea about the 'ajaxfile.php', please keep in mind that in order for this approach to work, you need to add an extra column to your db table (for example column: "seen" -that takes values 1 or 0 and having number 1 as default for every new row added). Since you didn't provide enough information, I will here assume that the database table is called "users" and -say- you want to monitor each new user registration in real time (with 10 seconds intervals).
PHP (ajaxfile.php)
<?php
//protect the file from un-authorized access
define('AJAX_REQUEST', isset($_SERVER['HTTP_X_REQUESTED_WITH']) && strtolower($_SERVER['HTTP_X_REQUESTED_WITH']) == 'xmlhttprequest');
if(!AJAX_REQUEST) {die();}
require("db_connect.php"); //a typical db connection function
$results = array(); //define the results variable
$query = mysql_query("SELECT * FROM users WHERE new_column = '1' ORDER BY id DESC LIMIT 1"); //here we query the db to fetch only the newest record -the one where column "seen" is "1"
while($res = mysql_fetch_assoc($query)){
$current_id = $res["id"];
mysql_query("UPDATE users SET new_column = '0' WHERE id = '$current_id' "); //update the record so it will appear as "seen" and will not be fetched again
$results[] = $res;
}
echo json_encode($results);
?>
In the above file, notice the first two lines which are there to protect the ajax file from direct "browser calls". It is quite a universal solution and can be used in all ajax files.
Finally, here is an example of the db_connect.php file:
<?php
define('DB_HOST', 'localhost'); // the database host
define('DB_PORT', '3306'); // the database port
define('DB_NAME', 'your_db_name'); // the database name
define('DB_USER', 'your_db_user'); // the database user
define('DB_PASSWORD', 'your_db_password'); // the database password
$conn = #mysql_connect(DB_HOST, DB_USER, DB_PASSWORD) or die("Could not connect to the Database Server");
mysql_select_db(DB_NAME, $conn) or die("Could not find the Database");
?>
It is a very general approach indeed, but can cover a wide spectrum of applications with small modifications or additions.
I am sorry I could not be more specific -but your question was also a bit too "general"... Hope this helps you and others.