Thank you for being here!

i want to be able to select acc_id from account_info table and insert it in patient_info table as Foreign Key

I am getting this error :

In my localhost i can see the value it’s suppose to return. And this error which I suppose it occurs because i haven’t inserted acc_id yet SQLSTATE[23000]: Integrity constraint violation: 1048 Column 'acc_id' cannot be null

Also var_dump($ data) returns array(1) { [0]=> object(stdClass)#3 (1) { ["acc_id"]=> int(124) } }

php file :

 <?php  header('Access-Control-Allow-Origin: *');  // Define database connection parameters $  hn      = 'localhost'; $  un      = 'root'; $  pwd     = ''; $  db      = 'ringabell'; $  cs      = 'utf8';  // Set up the PDO parameters $  dsn  = "mysql:host=" . $  hn . ";port=3306;dbname=" . $  db . ";charset=" . $  cs; $  opt  = array(                     PDO::ATTR_ERRMODE            => PDO::ERRMODE_EXCEPTION,                     PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_OBJ,                     PDO::ATTR_EMULATE_PREPARES   => false,                    ); // Create a PDO instance (connect to the database) $  pdo  = new PDO($  dsn, $  un, $  pwd, $  opt);  // Retrieve specific parameter from supplied URL $  data = array();        try{      $  stmt = $  pdo->query('SELECT acc_id FROM account_info ORDER BY acc_id DESC LIMIT 1');     $  data = $  stmt->fetchAll(PDO::FETCH_OBJ);         // Return data as JSON             echo json_encode($  data);              var_dump($  data);       $  sql= "INSERT INTO patient_info(acc_id, p_fname, p_lname, p_gender, p_condition, p_birthdate, p_emergencycontact)                                 VALUES(:data, :p_fname, :p_lname, :p_gender, :p_condition, :p_birthdate, :p_emergencycontact)";           $  stmt    = $  pdo->prepare($  sql);           $  stmt->bindParam(':p_fname', $  p_fname, PDO::PARAM_STR);         $  stmt->bindParam(':p_lname', $  p_lname, PDO::PARAM_STR);         $  stmt->bindParam(':p_gender', $  p_gender, PDO::PARAM_STR);         $  stmt->bindParam(':p_condition', $  p_condition, PDO::PARAM_STR);         $  stmt->bindParam(':p_birthdate', $  p_birthdate, PDO::PARAM_STR);         $  stmt->bindParam(':p_emergencycontact', $  p_emergencycontact, PDO::PARAM_STR);             $  stmt->bindParam(':data', $  acc_id, PDO::PARAM_STR);            $  stmt->execute();           echo json_encode(array('message' => 'Congratulations the record was added to the database'));     }      catch(PDOException $  e)      {         echo $  e->getMessage();      } ?>