$criteria = $request->get('criteria');
$data = DB::select(
    DB::raw("SELECT DISTINCT id, obtain_prefix.prefix, ".
        "(CASE WHEN prefix = 'WO' THEN number WHEN prefix = 'PN' THEN part_number WHEN prefix like 'COND%' THEN description ".
        "ELSE NULL END) AS right_value FROM (SELECT DISTINCT work_orders.id, work_orders.number AS number, ".
        "inventory_master.part_number AS part_number, part_conditions.description AS description, ".
        "(CASE WHEN number like :criteria THEN 'WO' WHEN part_number like :criteria THEN 'PN'".
        "WHEN part_conditions.description like '' THEN 'CONDITION' ELSE NULL END) AS prefix ".
        "FROM work_orders LEFT JOIN work_order_quotes ON work_order_quotes.work_order_id = work_orders.id ".
        "LEFT JOIN work_order_parts ON work_order_parts.work_order_quote_id = work_order_quotes.id ".
        "JOIN inventory_master ON work_order_parts.inventory_master_id = inventory_master.id ".
        "LEFT JOIN part_conditions ON part_conditions.id = work_order_parts.condition_id WHERE ".
        "work_order_status_id IN ( 1, 2, 3 )) obtain_prefix where prefix IS NOT NULL", compact('criteria))
);

DB::select(DB::raw("...query...", ['criteria' => $criteria]));

DB::select(DB::raw("...query...")->addBinding('criteria', $criteria));

DB::select(DB::raw("...query..."))->addBinding('criteria', $criteria);