@RequestMapping(value = "test/{id}", method = RequestMethod.GET)
 @ResponseBody
 public List<SqlDTO> getSqlTest(
     @PathVariable Integer id, @RequestHeader("sessionId") String sessionId) {
   if (loginService.isValidSessionId(sessionId) == true) {
     return sqlTestService.getSqlTest(id);
   } else return null;
 }
 @RequestMapping(value = "/", method = RequestMethod.POST)
 @ResponseBody
 public List<SqlDTO> answerSqlTestPost(@RequestBody List<SqlDTO> sqlDTOs) {
   return sqlTestService.answerSqlTestPost(sqlDTOs);
 }