Saving data to 2 tables in the database in CakePHP - php

Question

I have a simple sample project created to test how to add data to 2 tables from one controller in CakePHP, I have a tables called Student, Users, Admin and UserGroups. I need to add a Student to the database table and also add the students username and password to the users table. Here are the SQL for the tables.
CREATE TABLE `students` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`user_group_id` int(11) DEFAULT NULL,
`name` varchar(255) DEFAULT NULL,
`address` varchar(255) DEFAULT NULL,
`username` varchar(40) DEFAULT NULL,
`password` varchar(40) DEFAULT NULL,
`created` datetime DEFAULT NULL,
`modified` datetime DEFAULT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=6 DEFAULT CHARSET=latin1;
CREATE TABLE `users` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`user_group_id` int(11) DEFAULT NULL,
`created` datetime DEFAULT NULL,
`modified` datetime DEFAULT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1;
CREATE TABLE `user_groups` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`role` varchar(255) DEFAULT NULL,
`created` datetime DEFAULT NULL,
`modified` datetime DEFAULT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=3 DEFAULT CHARSET=latin1;
CREATE TABLE `admins` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`user_group_id` int(11) DEFAULT NULL,
`name` varchar(255) DEFAULT NULL,
`post` varchar(255) DEFAULT NULL,
`username` varchar(40) DEFAULT NULL,
`password` varchar(40) DEFAULT NULL,
`created` datetime DEFAULT NULL,
`modified` datetime DEFAULT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=2 DEFAULT CHARSET=latin1;
I created the following function to add the data to the Students table and the Users table.
public function add() {
if ($this->request->is('post')) {
$userGrp = $this->request->data['Student']['user_group_id'];
$username = $this->request->data['Student']['username'];
$pass = $this->request->data['Student']['password'];
$this->Student->create();
if ($this->Student->save($this->request->data)) {
$this->request->data['User']['user_group_id'] = $userGrp;
$this->request->data['User']['username'] = $username;
$this->request->data['User']['password'] = $pass;
if ($this->Student->User->save($this->request->data)) {
$this->Session->setFlash(__('The student has been saved. Both in to Student and User'));
return $this->redirect(array('action' => 'index'));
}
} else {
$this->Session->setFlash(__('The student could not be saved. Please, try again.'));
}
}
$userGroups = $this->Student->UserGroup->find('list');
$this->set(compact('userGroups'));
}
The model for the Student is as follows.
<?php
App::uses('AppModel', 'Model');
class Student extends AppModel {
public $displayField = 'name';
public $belongsTo = array(
'UserGroup' => array(
'className' => 'UserGroup',
'foreignKey' => 'user_group_id',
'conditions' => '',
'fields' => '',
'order' => ''
)
);
}
When i add the Student details in to the database following error shows. Data is sent to the Student table but not to the Users table
Error: Call to a member function save() on a non-object
File: D:\wamp\www\MultiTables\app\Controller\StudentsController.php
What am i doing wrong here? please help.

Answer 1

IMO, students and admins should all be in a table called 'users'.
Your table that you named "users" is really a join table. That is an incorrect name for a join table if you are following conventions.
Then you would have these models:
Users (belongsTo UserGroups)
UserGroups (habtm Users via UserGroupUsers)
UserGroupUsers (belongsTo Users & belongsTo UserGroups)
If linked like that, then these inputs would save data to all three tables:
$this->Form->input('User.username')
$this->Form->input('User.password')
$this->Form->input('UserGroup.id', array('value' => 15)
You should check out CakePHP's "bake" feature. If you give it a properly constructed database, it will help you make correctly linked models.
Seems that what you're currently trying to do is:
Students (belongsTo Users)
UserGroups (habtm Students via Users & habtm Admins via Users)
Users (belongsTo Students & belongsTo Users & belongsTo Admins)
$this->Form->input('Student.username')
$this->Form->input('User.password')
$this->Form->input('UserGroup.id', array('value' => 15)

Answer 2

Model Student is not associated with model User.
So when you do $this->Student->User->save() with no association defined in the Student Model, You will afterwards get the error you showed because Student does not know about User.
Try defining a model Association between Student and User Model like this: A student belongs to the User and a User belongs to a UserGroup
class Student extends AppModel {
public $displayField = 'name';
public $belongsTo = array(
'User' => array(
'className' => 'User',
'foreignKey' => 'user_id',
'conditions' => '',
'fields' => '',
'order' => ''
)
);
}
class User extends AppModel {
public $belongsTo = array(
'UserGroup' => array(
'className' => 'UserGroup',
'foreignKey' => 'user_group_id',
'conditions' => '',
'fields' => '',
'order' => ''
)
);
}
This assumes then that you rename your Student.user_group_id into a Student.user_id in your database. Now if you want to save the User from the Student controller you can either use:
$this->Student->User->save($this->request->data)
or use the saveAssociated() method like this $this->Student->saveAssociated($this->request->data) if you named your form fields correctly