cakephp - Postgresql データベースを使用した CakePhp 挿入の問題

Question

私はcakephpでこの問題を抱えています.テーブルusersとprofilesがあり、
profilesテーブルには外部キーuser_idがあり、usersテーブルのid列を参照しています.

挿入するとき、最初にユーザーのデータを挿入し、最後に挿入されたデータのIDをユーザーテーブルから取得してから、プロファイルテーブルにあるuser_idフィールドに渡します。問題は、このエラーが発生することです:

エラー: SQLSTATE[22P02]: 無効なテキスト表現: 7 エラー: 配列値は "{" またはディメンション情報で始まる必要があります

ここにデータ挿入のコードがあります。

/*
* signup method
* @return void
*/
public function signup(){
    if($this->request->is('post')){                             
        $this->User->create();
        //Tweek to unset modified field.
        $user_data = array(
            'username' => $this->request->data['User']['username'],
            'password' => $this->request->data['User']['password'],
            'modified' => false             
        );  
        $user = $this->User->save($user_data);
        if(!empty($user)){
            //If the user was saved get the users id and pass to profile user_id foreign key
            $this->request->data['Profile']['user_id'] = $this->User->id;

            // Because our User hasOne Profile, we can access
            // the Profile model through the User model
            $profile_data = array(
                'user_id' => $this->request->data['Profile']['user_id'],
                'student_id' => $this->request->data['Profile']['student_id'],
                'first_name' => $this->request->data['Profile']['first_name'],
                'middle_name' => $this->request->data['Profile']['middle_name'],
                'last_name' => $this->request->data['Profile']['last_name'],
                'modified' => false
            );
            if($this->User->Profile->save($profile_data)){
                $this->Session->setFlash(__('Your Account has been successfully added.'));
                return $this->redirect(array('action' => 'login'));
            }
            $this->Session->setFlash(__('The user could not be saved. Please, try again.'), 'default', array(), 'register_error');
        }
    }

    $this->layout = 'custom_layouts/default';
    $data = array(
        'id' => 'signup',
        'title_for_layout' => 'Reservation . Sign up'
    );
    $this->set($data);  
}   

ユーザーモデルは次のとおりです。

<?php   
App::uses('AuthComponent', 'Controller/Component');
App::uses('BlowfishPasswordHasher', 'Controller/Component/Auth');   

/**
 * User Model
 *
 */
class User extends AppModel {
    //Allow Model to use both users and profiles table
    public $uses = array('User', 'Profile');

    //Setting Models Association
    public $hasOne = array(
        'Profile' => array(
            'classname' => 'Profile',
            'order' => array('Profile.last_name' => 'ASC'),
            'dependent' => TRUE
        )
    );

    /**
     * Validation rules
     *
     * @var array
     */
    public $validate = array(
        'username' => array(
            'required' => array(
                'rule' => array('notEmpty'),
                'message' => 'A username is required'
            ),
            'isUnique' => array(
                'rule' => 'isUnique',
                'message' => 'This username has already been taken.'
            )
        ),
        'password' => array(
            'required' => array(
                'rule' => array('notEmpty'),
                'message' => 'A password is required'
            ),
            'minlength' => array(
                'rule' => array('minlength', '8'),
                'message' => 'Password should be 8 characters long'
            )
        )           
    );      

    public function beforeSave($options = array()){         
        //Hash passwords before saving to database          
        if(!empty($this->data[$this->alias]['password']) || isset($this->data[$this->alias]['password'])){
            $hashedPassword = Security::hash($this->data[$this->alias]['password'],"blowfish");
            $this->data[$this->alias]['password'] = $hashedPassword;
        }           
        return true;
    }       
}

プロファイルモデルは次のとおりです。

<?php       
/**
 * User Model
 *
 */
class Profile extends AppModel {
    //Setting Models Association
    public $belongsTo = array(
        'User' => array(
            'classname' => 'User',
            'foreignKey' => 'user_id'
        )
    );

    //Data Validation
    public $validate = array(
        'student_id' => array(
            'required' => array(
                'rule' => array('notEmpty'),
                'message' => 'A student id is required'
            ),
            'isUnique' => array(
                'rule' => 'isUnique',
                'message' => 'This student id has already been taken.'
            )
        ),

        'email' => array(
            'required' => array(
                'rule' => array('notEmpty'),
                'message' => 'An email is required'
            ),
            'isUnique' => array(
                'rule' => 'isUnique',
                'message' => 'This email address has already been taken.'
            )
        )
    );
}

ここにスキーマがあります