$(document).ready(function() {
  var table = $('#example').DataTable( {
    "processing": true,
    "serverSide": true,
    "paging": true,
    "pageLength": 10,
    "lengthChange": false,
    "bInfo": false,
    "ordering": false,
    "ajax": "server_processing.php",
    "columns": [

      { "data": "codigo_interno" },
      { "data": "otros_codigos" },
      { "data": "nombre_comun" },
      { "data": "compatibilidad" },
      { "data": "precio_final" },
      { "data": "cantidad" },
      {
      "targets": -1,
      "data": null,
      "defaultContent": "<button>Ver</button>"
      }
    ],


      "language": {
       search: "Buscar",
       "zeroRecords": "No existen registros"
   }
  } );

  $('#example tbody').on( 'click', 'button', function () {
   var data = table.row( $(this).parents('tr') ).data();
   //alert( data['codigo_interno'] );
   var hola =  data['codigo_interno'];
   location.href="index2.php?id="+hola;


  } );


  } );

<?php
$table = 'repuestosfinal';
$primaryKey = 'id_repuestos';


$columns = array(
array( 'db' => 'codigo_interno', 'dt' => 'codigo_interno' ),
array( 'db' => 'otros_codigos',  'dt' => 'otros_codigos' ),
array( 'db' => 'nombre',   'dt' => 'nombre_comun' ),
array( 'db' => 'compatibilidad',     'dt' => 'compatibilidad' ),
array( 'db' => 'precio_final',     'dt' => 'precio_final' ),
array( 'db' => 'cantidad',     'dt' => 'cantidad' )

);

$sql_details = array(
'user' => 'root',
'pass' => '',
'db'   => 'urizar',
'host' => 'localhost'
);


require( 'ssp.class.php' );

echo json_encode(
    SSP::simple( $_GET, $sql_details, $table, $primaryKey, $columns )
);

<?php

// REMOVE THIS BLOCK - used for DataTables test environment only!
$file = $_SERVER['DOCUMENT_ROOT'].'/datatables/pdo.php';
if ( is_file( $file ) ) {
include( $file );
}
class SSP {
/**
 * Create the data output array for the DataTables rows
 *
 *  @param  array $columns Column information array
 *  @param  array $data    Data from the SQL get
 *  @return array          Formatted data in a row based format
 */
static function data_output ( $columns, $data )
{
    $out = array();
    for ( $i=0, $ien=count($data) ; $i<$ien ; $i++ ) {
        $row = array();
        for ( $j=0, $jen=count($columns) ; $j<$jen ; $j++ ) {
            $column = $columns[$j];
            // Is there a formatter?
            if ( isset( $column['formatter'] ) ) {
                $row[ $column['dt'] ] = $column['formatter']( $data[$i][ $column['db'] ], $data[$i] );
            }
            else {
                $row[ $column['dt'] ] = $data[$i][ $columns[$j]['db'] ];
            }
        }
        $out[] = $row;
    }
    return $out;
}
/**
 * Database connection
 *
 * Obtain an PHP PDO connection from a connection details array
 *
 *  @param  array $conn SQL connection details. The array should have
 *    the following properties
 *     * host - host name
 *     * db   - database name
 *     * user - user name
 *     * pass - user password
 *  @return resource PDO connection
 */
static function db ( $conn )
{
    if ( is_array( $conn ) ) {
        return self::sql_connect( $conn );
    }
    return $conn;
}
/**
 * Paging
 *
 * Construct the LIMIT clause for server-side processing SQL query
 *
 *  @param  array $request Data sent to server by DataTables
 *  @param  array $columns Column information array
 *  @return string SQL limit clause
 */
static function limit ( $request, $columns )
{
    $limit = '';
    if ( isset($request['start']) && $request['length'] != -1 ) {
        $limit = "LIMIT ".intval($request['start']).", ".intval($request['length']);
    }
    return $limit;
}
/**
 * Ordering
 *
 * Construct the ORDER BY clause for server-side processing SQL query
 *
 *  @param  array $request Data sent to server by DataTables
 *  @param  array $columns Column information array
 *  @return string SQL order by clause
 */
static function order ( $request, $columns )
{
    $order = '';
    if ( isset($request['order']) && count($request['order']) ) {
        $orderBy = array();
        $dtColumns = self::pluck( $columns, 'dt' );
        for ( $i=0, $ien=count($request['order']) ; $i<$ien ; $i++ ) {
            // Convert the column index into the column data property
            $columnIdx = intval($request['order'][$i]['column']);
            $requestColumn = $request['columns'][$columnIdx];
            $columnIdx = array_search( $requestColumn['data'], $dtColumns );
            $column = $columns[ $columnIdx ];
            if ( $requestColumn['orderable'] == 'true' ) {
                $dir = $request['order'][$i]['dir'] === 'asc' ?
                    'ASC' :
                    'DESC';
                $orderBy[] = '`'.$column['db'].'` '.$dir;
            }
        }
        if ( count( $orderBy ) ) {
            $order = 'ORDER BY '.implode(', ', $orderBy);
        }
    }
    return $order;
}
/**
 * Searching / Filtering
 *
 * Construct the WHERE clause for server-side processing SQL query.
 *
 * NOTE this does not match the built-in DataTables filtering which does it
 * word by word on any field. It's possible to do here performance on large
 * databases would be very poor
 *
 *  @param  array $request Data sent to server by DataTables
 *  @param  array $columns Column information array
 *  @param  array $bindings Array of values for PDO bindings, used in the
 *    sql_exec() function
 *  @return string SQL where clause
 */
static function filter ( $request, $columns, &$bindings )
{
    $globalSearch = array();
    $columnSearch = array();
    $dtColumns = self::pluck( $columns, 'dt' );
    if ( isset($request['search']) && $request['search']['value'] != '' ) {
        $str = $request['search']['value'];
        for ( $i=0, $ien=count($request['columns']) ; $i<$ien ; $i++ ) {
            $requestColumn = $request['columns'][$i];
            $columnIdx = array_search( $requestColumn['data'], $dtColumns );
            $column = $columns[ $columnIdx ];
            if ( $requestColumn['searchable'] == 'true' ) {
                $binding = self::bind( $bindings, '%'.$str.'%',
PDO::PARAM_STR );
                $globalSearch[] = "`".$column['db']."` LIKE ".$binding;
            }
        }
    }
    // Individual column filtering
    if ( isset( $request['columns'] ) ) {
        for ( $i=0, $ien=count($request['columns']) ; $i<$ien ; $i++ ) {
            $requestColumn = $request['columns'][$i];
            $columnIdx = array_search( $requestColumn['data'], $dtColumns );
            $column = $columns[ $columnIdx ];
            $str = $requestColumn['search']['value'];
            if ( $requestColumn['searchable'] == 'true' &&
             $str != '' ) {
                $binding = self::bind( $bindings, '%'.$str.'%',
PDO::PARAM_STR );
                $columnSearch[] = "`".$column['db']."` LIKE ".$binding;
            }
        }
    }
    // Combine the filters into a single string
    $where = '';
    if ( count( $globalSearch ) ) {
        $where = '('.implode(' OR ', $globalSearch).')';
    }
    if ( count( $columnSearch ) ) {
        $where = $where === '' ?
            implode(' AND ', $columnSearch) :
            $where .' AND '. implode(' AND ', $columnSearch);
    }
    if ( $where !== '' ) {
        $where = 'WHERE '.$where;
    }
    return $where;
}
/**
 * Perform the SQL queries needed for an server-side processing requested,
 * utilising the helper functions of this class, limit(), order() and
 * filter() among others. The returned array is ready to be encoded as JSON
 * in response to an SSP request, or can be modified if needed before
 * sending back to the client.
 *
 *  @param  array $request Data sent to server by DataTables
 *  @param  array|PDO $conn PDO connection resource or connection parameters
array
 *  @param  string $table SQL table to query
 *  @param  string $primaryKey Primary key of the table
 *  @param  array $columns Column information array
 *  @return array          Server-side processing response array
 */
static function simple ( $request, $conn, $table, $primaryKey, $columns )
{
    $bindings = array();
    $db = self::db( $conn );
    // Build the SQL query string from the request
    $limit = self::limit( $request, $columns );
    $order = self::order( $request, $columns );
    $where = self::filter( $request, $columns, $bindings );
    // Main query to actually get the data
    $data = self::sql_exec( $db, $bindings,
        "SELECT `".implode("`, `", self::pluck($columns, 'db'))."`
         FROM `$table`
         $where
         $order
         $limit"
    );
    // Data set length after filtering
    $resFilterLength = self::sql_exec( $db, $bindings,
        "SELECT COUNT(`{$primaryKey}`)
         FROM   `$table`
         $where"
    );
    $recordsFiltered = $resFilterLength[0][0];
    // Total data set length
    $resTotalLength = self::sql_exec( $db,
        "SELECT COUNT(`{$primaryKey}`)
         FROM   `$table`"
    );
    $recordsTotal = $resTotalLength[0][0];
    /*
     * Output
     */
    return array(
        "draw"            => isset ( $request['draw'] ) ?
            intval( $request['draw'] ) :
            0,
        "recordsTotal"    => intval( $recordsTotal ),
        "recordsFiltered" => intval( $recordsFiltered ),
        "data"            => self::data_output( $columns, $data )
    );
}
/**
 * The difference between this method and the `simple` one, is that you can
 * apply additional `where` conditions to the SQL queries. These can be in
 * one of two forms:
 *
 * * 'Result condition' - This is applied to the result set, but not the
 *   overall paging information query - i.e. it will not effect the number
 *   of records that a user sees they can have access to. This should be
 *   used when you want apply a filtering condition that the user has sent.
 * * 'All condition' - This is applied to all queries that are made and
 *   reduces the number of records that the user can access. This should be
 *   used in conditions where you don't want the user to ever have access to
 *   particular records (for example, restricting by a login id).
 *
 *  @param  array $request Data sent to server by DataTables
 *  @param  array|PDO $conn PDO connection resource or connection parameters
array
 *  @param  string $table SQL table to query
 *  @param  string $primaryKey Primary key of the table
 *  @param  array $columns Column information array
 *  @param  string $whereResult WHERE condition to apply to the result set
 *  @param  string $whereAll WHERE condition to apply to all queries
 *  @return array          Server-side processing response array
 */
static function complex ( $request, $conn, $table, $primaryKey, $columns,
$whereResult=null, $whereAll=null )
{
    $bindings = array();
    $db = self::db( $conn );
    $localWhereResult = array();
    $localWhereAll = array();
    $whereAllSql = '';
    // Build the SQL query string from the request
    $limit = self::limit( $request, $columns );
    $order = self::order( $request, $columns );
    $where = self::filter( $request, $columns, $bindings );
    $whereResult = self::_flatten( $whereResult );
    $whereAll = self::_flatten( $whereAll );
    if ( $whereResult ) {
        $where = $where ?
            $where .' AND '.$whereResult :
            'WHERE '.$whereResult;
    }
    if ( $whereAll ) {
        $where = $where ?
            $where .' AND '.$whereAll :
            'WHERE '.$whereAll;
        $whereAllSql = 'WHERE '.$whereAll;
    }
    // Main query to actually get the data
    $data = self::sql_exec( $db, $bindings,
        "SELECT `".implode("`, `", self::pluck($columns, 'db'))."`
         FROM `$table`
         $where
         $order
         $limit"
    );
    // Data set length after filtering
    $resFilterLength = self::sql_exec( $db, $bindings,
        "SELECT COUNT(`{$primaryKey}`)
         FROM   `$table`
         $where"
    );
    $recordsFiltered = $resFilterLength[0][0];
    // Total data set length
    $resTotalLength = self::sql_exec( $db, $bindings,
        "SELECT COUNT(`{$primaryKey}`)
         FROM   `$table` ".
        $whereAllSql
    );
    $recordsTotal = $resTotalLength[0][0];
    /*
     * Output
     */
    return array(
        "draw"            => isset ( $request['draw'] ) ?
            intval( $request['draw'] ) :
            0,
        "recordsTotal"    => intval( $recordsTotal ),
        "recordsFiltered" => intval( $recordsFiltered ),
        "data"            => self::data_output( $columns, $data )
    );
}
/**
 * Connect to the database
 *
 * @param  array $sql_details SQL server connection details array, with the
 *   properties:
 *     * host - host name
 *     * db   - database name
 *     * user - user name
 *     * pass - user password
 * @return resource Database connection handle
 */
static function sql_connect ( $sql_details )
{
    try {
        $db = @new PDO(
            "mysql:host={$sql_details['host']};dbname={$sql_details['db']}",
            $sql_details['user'],
            $sql_details['pass'],
            array( PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION )
        );
    }
    catch (PDOException $e) {
        self::fatal(
            "An error occurred while connecting to the database. ".
            "The error reported by the server was: ".$e->getMessage()
        );
    }
    return $db;
}
/**
 * Execute an SQL query on the database
 *
 * @param  resource $db  Database handler
 * @param  array    $bindings Array of PDO binding values from bind() to be
 *   used for safely escaping strings. Note that this can be given as the
 *   SQL query string if no bindings are required.
 * @param  string   $sql SQL query to execute.
 * @return array         Result from the query (all rows)
 */
static function sql_exec ( $db, $bindings, $sql=null )
{
    // Argument shifting
    if ( $sql === null ) {
        $sql = $bindings;
    }
    $stmt = $db->prepare( $sql );
    //echo $sql;
    // Bind parameters
    if ( is_array( $bindings ) ) {
        for ( $i=0, $ien=count($bindings) ; $i<$ien ; $i++ ) {
            $binding = $bindings[$i];
            $stmt->bindValue( $binding['key'], $binding['val'],
$binding['type'] );
        }
    }
    // Execute
    try {
        $stmt->execute();
    }
    catch (PDOException $e) {
        self::fatal( "An SQL error occurred: ".$e->getMessage() );
    }
    // Return all
    return $stmt->fetchAll( PDO::FETCH_BOTH );
}
/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
 * Internal methods
 */
/**
 * Throw a fatal error.
 *
 * This writes out an error message in a JSON string which DataTables will
 * see and show to the user in the browser.
 *
 * @param  string $msg Message to send to the client
 */
static function fatal ( $msg )
{
    echo json_encode( array(
        "error" => $msg
    ) );
    exit(0);
}
/**
 * Create a PDO binding key which can be used for escaping variables safely
 * when executing a query with sql_exec()
 *
 * @param  array &$a    Array of bindings
 * @param  *      $val  Value to bind
 * @param  int    $type PDO field type
 * @return string       Bound key to be used in the SQL where this parameter
 *   would be used.
 */
static function bind ( &$a, $val, $type )
{
    $key = ':binding_'.count( $a );
    $a[] = array(
        'key' => $key,
        'val' => $val,
        'type' => $type
    );
    return $key;
}
/**
 * Pull a particular property from each assoc. array in a numeric array,
 * returning and array of the property values from each item.
 *
 *  @param  array  $a    Array to get data from
 *  @param  string $prop Property to read
 *  @return array        Array of property values
 */
static function pluck ( $a, $prop )
{
    $out = array();
    for ( $i=0, $len=count($a) ; $i<$len ; $i++ ) {
        $out[] = $a[$i][$prop];
    }
    return $out;
}
/**
 * Return a string from an array or a string
 *
 * @param  array|string $a Array to join
 * @param  string $join Glue for the concatenation
 * @return string Joined string
 */
static function _flatten ( $a, $join = ' AND ' )
{
    if ( ! $a ) {
        return '';
    }
    else if ( $a && is_array($a) ) {
        return implode( $join, $a );
    }
    return $a;
}
}