I have an application using html, javascript w/jquery and php in the server side. The application sends $.ajax() requisitions to the server (php files) that then returns to me a result.
What happens, it's that I have a very big sql query that it's taking too long to load because of the number of rows returned and because some conversions that I have to do to them.
How can I split this big query in small others?
Or how can I do a small query, show it results then do another query that begins from the position that the other stopped?(without duplicating the results).
ps: I already tried array_chunk but it wont't worked. It's shows me the same number of rows. When I tried to show via javascript, it returns me as undefined
Here is a fragment of code:(.php)
//I made the connetion and all the queries using PDO
$sql = $pdo->prepare("SELECT field1,field2,field3,field4 FROM table WHERE st <> 'C-CONDITION' ");
$sql->execute();
$result = $sql->fetchAll();
$answer['dt'] = $r;
//here i'm sending the result to the client(javascript) on JSON format.
echo json_encode($retorno,JSON_PRETTY_PRINT);
