title: DataTables Server Side Individual Column Filtering
body: <p>I was hoping someone can help me with this. I have been running myself crazy with this.</p>
  
  <p>I have a situation where I load the DataTables grid (awesome piece by the way!) and all is great. Then I go to search and I run into problems. The data being populated in the grid is coming from two different database tables (which is fine) but when someone executes a search I have no way of knowing where to go and get the data. I would need to know what criteria the search is about (i.e. title or contact). I see what when the search is called from the server via the default search box there are variables like "sSearch_0" which are all unset, how do those get set?</p>
  
  <p>Here is the initialization code for the table:</p>
  
  <pre><code>oTable = $('#example').dataTable({
  "bJQueryUI": true,
  "bFilter": true,
  "sPaginationType": "full_numbers",
  "bPaginate " : true,
  "bServerSide" : true,
  "sAjaxSource" : "php/tabledata.php",
  "aoColumnDefs": [
       { "bSortable": false, "aTargets": [ 0,6,8 ] },
   { "sClass": "tdCenter", "aTargets": [ 0,1,2,3,4,5,6,7,8 ] }
       ],
  "fnServerData": function ( sSource, aoData, fnCallback ) {
  aoData.push( { "name": "userid", "value": userid } );
  $.getJSON( sSource, aoData, function (json) { 
  fnCallback(json)
  });
  }           
  </code></pre>
  
  <p>});</p>
  
  <p>I have looked into options for adding data to the "fnServerData " and actually use that for the first initialization server call but am unsure how to use that for a subsequent server call. I have tried to use "fnFilter" but I do not see that executing a server call for more data. At this point I do not see any other way to execute a server call besides the default search box and I see some way of knowing which column the search is for.</p>
  
  <p>Can someone help me here and point me in the right direction?</p>