enable search and filtering on server-side datatable using foreign keys names not id's

Hi guys,
i am using server-side datatable, i have 2 foreign keys, i am showing not id's but name in other table. But when i make search and enter names it doesn't work, i want to enable search only in showed attributes. Thanks

<?php
    //include connection file 
    include_once("connection.php");
     
    // initilize all variable
    $params = $columns = $totalRecords = $data = array();

    $params = $_REQUEST;


        $columns = array( 'id_doc','ref','taille','date_ajout' , 'type', 'nature', 'date_doc', 'date_echeance', 'date_notif', 'date_modif');

    $where = $sqlTot = $sqlRec = "";

    // check search value exist
    if( !empty($params['search']['value']) ) {   
        $where .=" WHERE ";
        $where .=" ( id_doc LIKE '%".mysql_real_escape_string($params['search']['value'])."%' ";
        $where .=" OR date_ajout LIKE '%".mysql_real_escape_string($params['search']['value'])."%' ";
        $where .=" OR type LIKE '%".mysql_real_escape_string($params['search']['value'])."%' ";
        $where .=" OR nature LIKE '%".mysql_real_escape_string($params['search']['value'])."%' ";
        $where .=" OR date_doc LIKE '%".mysql_real_escape_string($params['search']['value'])."%' ";
        $where .=" OR date_echeance LIKE '%".mysql_real_escape_string($params['search']['value'])."%' ";
        $where .=" OR date_notif LIKE '%".mysql_real_escape_string($params['search']['value'])."%' ) ";

    }

    // getting total number records without any search
    $sql = "SELECT * FROM `document` ";
    $sqlTot .= $sql;
    $sqlRec .= $sql;
    //concatenate search sql if value exist
    if(isset($where) && $where != '') {

        $sqlTot .= $where;
        $sqlRec .= $where;
    }


    $sqlRec .=  " ORDER BY ". $columns[$params['order'][0]['column']]."   ".$params['order'][0]['dir']."  LIMIT ".$params['start']." ,".$params['length']." ";

    $queryTot = mysqli_query($conn, $sqlTot) or die("database error:". mysqli_error($conn));


    $totalRecords = mysqli_num_rows($queryTot);

    $queryRecords = mysqli_query($conn, $sqlRec) or die("erreur en affichant l historique");

    //iterate on results row and create new index array of data
include 'connect.php';
    while ( $aRow = mysqli_fetch_array( $queryRecords ) ){
    
    $row = array();
            for ( $i=0 ; $i<count($columns) ; $i++ )
        {
            if ( $columns[$i] == "type" )
            {   
                /* Special output formatting for 'version' column */
                $comp=$aRow[ $columns[$i] ];
                
                        $sql="SELECT * FROM document_type where id_type='$comp'";
                        $req= mysql_query ($sql) ;
                        $datay= mysql_fetch_array($req);
                        $val = $datay['nom'];
                        
                        $row[] = $val;
                
            } 
             else if ( $columns[$i] != ' ' )
            {
                /* General output */
                $row[] = $aRow[ $columns[$i] ];
            }

        }
     //$output['data'][] = $row;
        $data[] = $row;
    }
    
    

    $json_data = array(
            "draw"            => intval( $params['draw'] ),   
            "recordsTotal"    => intval( $totalRecords ),  
            "recordsFiltered" => intval($totalRecords),
            "data"            => $data   // total data array
            );

    echo json_encode($json_data);  // send data as json format
?>

Edited by Colin - Syntax highlighting. Details on how to highlight code using markdown can be found in this guide.

[And joined two threads together as both stuck in spam filter]