PHP : get data from database - php

Question

I am making a web service in php.
I want to have data from database in pagination manner.
eg : I should have 10 records based on event_id which i am passing in url along with page_number i.e 10 records on 1st page , another 10 records on 2nd page, and so on.
I am very new to web service.
<?php
http://localhost/Mobile%20Webservice/customAppEngine/faq.php?Faq_request={"faq_event_id":"302","page_number":"1"}
if(isset($_REQUEST["Faq_request"]) && trim($_REQUEST["Faq_request"]) != '') {
$faq_details_Request = $_REQUEST["Faq_request"];
// $page_number = 1;
$faqeventdetails_o = json_decode($faq_details_Request);
if( isset($faqeventdetails_o->faq_event_id))
{
// event_id
$event_id = $faqeventdetails_o->faq_event_id;
if(trim($event_id)==''){
die($msgobj->customFailMessage("Please provide Event Id"));
}
$userQuery="SELECT * FROM `faq` WHERE faq_event_id=$event_id";
$u=mysql_query($userQuery);
$number=mysql_num_rows($u);
/* if($number>0){
$query="DELETE FROM `agendaLikes` WHERE event_id=$event_id and user_id=$user_id
and agenda_id=$agenda_id";
mysql_query($query);
mysql_query("UPDATE agenda SET agendaLikes=agendaLikes-1 where agenda_id=$agenda_id");
$arr['isLike']=0;
}else{
mysql_query("INSERT INTO `agendaLikes`(agenda_id,user_id,event_id) VALUES($agenda_id,$user_id,$event_id)");
$arr['isLike']=1;
mysql_query("UPDATE agenda SET agendaLikes=agendaLikes+1 where agenda_id=$agenda_id");
}*/
$arr['status']=$msgobj->success;
echo json_encode($u);
}
else {
die($msgobj->customFailMessage($msgobj->missingparamater));
}
}
else {
die($msgobj->customFailMessage($msgobj->invalidparamater));
}
based on faq_event_id i should get data.
when i hit in url then nothing is displayed.
where m I lacking?
Thank You.

Answer 1

Use Offset And Limit in your sql query
let's say you want 10 records for each page then you need to pass page parameter.
so for Example
$page = 2; //parameter pass by get or post method
$limit = 10 //our limit to get data per page
$offset = $page*$limit; //calculate your offset
Then your sql will look like
$userQuery="SELECT * FROM faq WHERE faq_event_id=$event_id ORDER BY id LIMIT $limit OFFSET $offeset";
Hope this works for you.

Answer 2

You can use below code as well.
//Need to set this variable when you send request to get next 10 records, default value would be 1
$page=1;
$offset = 10;
$limit = ($page - 1) * 10;
$userQuery="$userQuery="SELECT * FROM faq WHERE faq_event_id=$event_id ORDER BY id";
if($page > 0)
$userQuery .= " limit $limit, $offset";