Question

I am trying to pass data to a php page via ajax, the data gets inserted to the database, then I need to pick up the last insert and pass the back to update a select menu with that last insert selected. The database gets updated correctly, but Im getting a NULL return for the echo json_echo($data);

Been stuck on this all day, would really appreciate the help!!!

if (empty($_POST) === false && empty($errors) === true) {

      $company_id   = $_POST['company_id'];
      $patient_id   = $_POST['addpatient_id'];
      $first_name   = $_POST['addpatient_firstname'];
      $last_name    = $_POST['addpatient_lastname'];
      $dob          = $_POST['addpatient_dob'];
      $updated      = $_POST['patient_added'];


      $update = array();
      array_walk($update_data, 'array_sanitize');

      foreach($update_data as $field=>$data) {
          $update[] = '`' . $field . '` = \'' . $data . '\'';
      }

      mysql_query("INSERT INTO `lab`.`patients` (`company_id`, `patient_firstname`, `patient_lastname`, `patient_dob`, `patient_added`) VALUES ('$company_id', '$first_name', '$last_name', '$dob', '$updated')");
      $last_patient_id = mysql_insert_id();

      $result = mysql_query("SELECT `patient_id`, `patient_firstname`, `patient_lastname`, `patient_dob` FROM `patients` WHERE `patient_id` = $last_patient_id");
      $data[] = mysql_fetch_assoc($result);
}
      echo json_encode( $data );

Answer 1

json_encode returns false if an error happened (php manual). I would start there.

$json_string = json_encode( $data );
if( $json_string ){
   echo $json_string;
}else{
   echo "Error";
   echo "<pre>";
   print_r($data);
   echo "</pre>";
}

That should at least lead you a way to debug.

EDIT: Also try add this to the beginning of the function all

error_reporting(E_ALL); 
ini_set('display_errors', '1'); 

This will help display errors that the mysql is throwing.

EDIT: I wanted to just fix spelling, but since I need 6 characters minimum I will mention http://jsonlint.com/ to validate what you’re putting into json_encode