I am working on a private messaging system using PHP-ActiveRecord ORM. I have models called 'User' and 'Message', MySQL tables called 'users' and 'messages', and in the messages table, I have fields called 'sender_id' and 'recipient_id'. However, I have no idea how to properly associate senders and recipients to the User model.
This is what I have so far in the User model:
static $has_many = array(
array('messages'),
array('recipients', 'foreign_key' => 'recipient_id', 'class_name' => 'Message'),
array('senders', 'foreign_key' => 'sender_id', 'class_name' => 'Message'),
);
and this is what I have so far in the Message model:
static $belongs_to = array(
array('sender', 'class_name' => 'User'),
array('recipient', 'class_name' => 'User'),
);
However, when I run the code such as $message->recipient->first_name, it does not properly pull the first name from the User model, like I want it to. I am not sure what I am doing wrong.
Normally, I just use the standard naming conventions. However, for this example, we have to have sender_id and recipient_id, which are both the same type, so I can't just use the standard naming conventions as I have been doing.
Any help would be highly appreciated. I am using the PHP-ActiveRecord ORM. I think the Rails version is more widely used, but it is my understanding that they work the same except with different syntax.
You also need to specify the foreign keys in the $belong_to, otherwise they will be inferred from the table's name (i.e. user_id):
static $belongs_to = array(
array('sender', 'class_name' => 'User', 'foreign_key' => 'sender_id'),
array('recipient', 'class_name' => 'User', 'foreign_key' => 'recipient_id'),
);
Related
How can I use has_one and has_many in codeigniter 3.0?
I would like to create relations through tables like in Ruby on Rails.
I.E
Class User
{
has_many: comments
}
Class Comments
{
belongs_to: users
}
This is the most common usage, and is used in almost every project. There is a simple pattern to defining this relationship.
Post has a creator and an editor, which may be different users. Here's how to set that up.
Post
class Post extends DataMapper {
$has_one = array(
'creator' => array(
'class' => 'user',
'other_field' => 'created_post'
),
'editor' => array(
'class' => 'user',
'other_field' => 'edited_post'
)
);
}
User
class User extends DataMapper {
$has_many = array(
'created_post' => array(
'class' => 'post',
'other_field' => 'creator'
),
'edited_post' => array(
'class' => 'post',
'other_field' => 'editor'
)
);
}
A couple of things to note here.
The relationship is now defined by the relationship key on either
side, not the model name. This has now become the only way to look
up the relationship.
The key on one side of the relationship becomes the other_field on
the opposite side, and vice-versa.
Because we need a way to specify the difference between posts that
were edited and those that were created, we have to declare the
slightly unusual edited_post and created_post relationships. These
could have any name, as long as they were unique and mirrored on
Post.
http://datamapper.wanwizard.eu/pages/advancedrelations.html
I have HABTM for Users and Groups. I want to show in a Group view - all the Groups that belong to a User. Or to put it differently - all the Groups that have the User.
I am getting tangled in the MVC and am not able to figure it out. Here are my two models:
class Course extends AppModel
public $name = 'Course';
public $hasAndBelongsToMany = array('User' =>
array(
'unique' => false
)
);
And...
public $name = 'User';
public $hasAndBelongsToMany = array('Course' =>
array(
'unique' => true
)
);
The table name in the database is courses_users - this table houses group ids and user ids.
Should be simple enough but I'm new to CakePHP so I'd love some help. Thank you!
CakePHP has recursive set to 1 by default, which means that assuming you have not changed the recursive setting, it will automatically fetch all associated courses when you call find on a user, assuming you set up the HABTM relationship when doing the find. Therefore, all you have to do is:
$this->User->find('first', array('conditions' => array('User.id' => $this->Auth->user('id'))));
In your User model, I don't think it's strictly necessary, but I like to specify the join table and such on HABTM relationships:
public $hasAndBelongsToMany = array('Course' =>
array(
'unique' => true,
'dependent' => false,
'joinTable' => 'courses_users',
'foreignKey' => 'user_id',
'associationForeignKey' => 'course_id',
)
);
Keep in mind that in HABTM relationships, you don't ever really touch the joinTable beyond specifying which table to use as the joinTable when setting up the relationship. CakePHP will automatically do the rest of the work.
I'm trying to insert into the table of a model with multiple levels of HasMany relationships. Here's the breakdown so far
Customer->(HasMany)->Members->(HasMany)->Incomes
However, on when trying to insert into the Incomes table, I get a "Not null violation" with the foreign key from the Members table not being carried to Incomes. I know the most common problem is screwing up the $_has_many and $_belongs_to properties, but as far as I can tell they are fine. Plus, Just inserting into the Member table works fine so I know at least for the first layer it's working! The only thing I can think of is if since it's a second level down, it's screwing up because of that. Here's my code:
Relation Link (Member)
protected static $_has_many = array(
'incomes' => array(
'key_from' => 'id',
'model_to' => 'Model_Income',
'key_to' => 'member_id',
'cascade_save' => true,
'cascade_delete' => true,
),
);
Relation Link (Income)
protected static $_belongs_to = array(
'member' => array(
'key_from' => 'member_id',
'model_to' => 'Model_Member',
'key_to' => 'id',
'cascade_save' => true,
'cascade_delete' => true,
),
);
The Controller Code
// code to set up $customer
$customer->members[] = Model_Member::forge();
// set $member_vals here
$customer->members[0]->set($member_vals);
$customer->members[0]->incomes[] = Model_Income::forge();
// set $income_vals here
$customer->members[0]->incomes[0]->set($income_vals);
$customer->save();
The first problem that comes to mind is that you're setting relations on ->members and ->incomes (plural), instead of ->member and ->income (singular).
I also prefer to do relations separately, instead of chaining them like you do. So, if you already have relations set when you're adding a new Member to Customer, or a new Income to Member, my guess is that the index will not be 0.
What if you try the following instead:
$member = Model_Member::forge($member_vals);
$income = Model_Income::forge($income_vals);
$member->income[] = $income;
$customer->member[] = $member;
$customer->save();
Does it work?
Different suggestion:
Since it appears that you're following the table/column naming convention, try only this:
// Model_Member
protected static $_has_many = array(
'incomes'
);
// Model_Income
protected static $_belongs_to = array(
'members' // plural, not singular like you seem to have
);
If you want more help, you should definitely show how you have the Member/Income models and tables.
I read a book Pactpub Web Application Development with Yii and PHP Nov 2012. Faced with such a problem, I can not understand the logic behind the use of relations (). Here diagram tables in the database:
You need to insert code in the model:
Issue model:
...
'requester' => array(self::BELONGS_TO, 'User', 'requester_id'),
'owner' => array(self::BELONGS_TO, 'User', 'owner_id'),
'project' => array(self::BELONGS_TO, 'Project', 'project_id'),
);
...
Project model:
...
'issues' => array(self::HAS_MANY, 'Issue', 'project_id'),
'users' => array(self::MANY_MANY, 'User', 'tbl_project_user_assignment(project_id, user_id)'),
...
I can not understand that we add? If the model Issue understand everything, then the model Project - I do not understand that we are adding. Help to understand ...
If the model Issue understand everything, then the model Project - I
do not understand that we are adding
in some case, you have already had a project, and you would like to find all of issues and partner users of that project.
$project = Project::model()->findByPK(1); // get project id=1
$issues = $project->issues; // get all of issues of project id=1, the result would be array
$users = $project->issues; // get all of users of project id=1, the result would be array
$project = Project::model()->with('issues', 'users')->findAll(); // get all of projects which has issue and user
//you have a user name ABC, and you want to find all of projects which contains a issue from owner has that user name.
$projects = Project::model()->with(array(
'issues' => array(
'alias' => 'issue',
//'condition' => '',
//'params' => array(),
'with' => array(
'owner'=>array(
'alias' => 'user',
'condition' => 'username =:username',
'params' => array(':username'=>'ABC'),
)
)
),
))->findAll();
There has many ways let you mix them up with multiple relations and conditions. One of above example would generate some big SQL SELECT query that I never want to deal with on my own :)
AR Relations Details
I'm using php.activerecord, and I am trying to link tables together. I'm not using their structure, but php.activerecord assumes I am, so it doesn't always work. I'm trying to use it on an already made app, so I can't change the database.
I learned from my previous question - Model association with custom table and key names - that I need to be as explicit as possible with the primary_key and foreign_key fields.
I'm having issues now using has_many through. I keep getting NULL, and I have no idea why.
So, here's a scenario: I have 3 tables, contacts, contactPrefs, and preferences. Those tables are as follows
contacts
--------
contactID
name
status
contactPrefs
------------
contactID
prefID
prefValue
preferences
-----------
prefID
name
description
Each contact has multiple contactPrefs. Each contactPrefs has one preferences. I tried to use has_many to get this working, but it's not. Here are my models:
Contacts.php:
<?php
class Contact extends ActiveRecord\Model {
static $primary_key = 'contactID';
static $has_many = array(
array(
'prefs',
'foreign_key' => 'contactid',
'primary_key' => 'contactid',
'class_name' => 'ContactPref'
),
array(
'preferences',
'foreign_key' => 'prefid',
'primary_key' => 'prefid',
'through' => 'prefs',
'class_name' => 'Preference'
)
);
}
ContactPref.php:
<?php
class ContactPref extends ActiveRecord\Model {
static $table_name = 'contactPrefs';
static $belongs_to = array(
array(
'contact',
'foreign_key' => 'contactid',
'primary_key' => 'contactid'
),
array(
'preference',
'foreign_key' => 'prefid',
'primary_key' => 'prefid'
)
);
}
Preference.php:
<?php
class Preference extends ActiveRecord\Model {
static $primary_key = 'prefID';
static $has_many = array(
array(
'prefs',
'foreign_key' => 'prefid',
'primary_key' => 'prefid',
'class_name' => 'ContactPref'
)
);
}
According to the docs, I now should be able to the following:
<?php
var_dump(Contact::find(1234)->preference);
I cannot. I get NULL. Oddly, I can do this:
<?php
var_dump(Contact::find(1234)->prefs[0]->preference);
That works correctly. But, shouldn't I be able to access the preference object directly through the contact object? Am I misunderstanding the docs (they aren't the greatest, in my opinion)? Am I doing something wrong?
First you are reading the docs with a small flaw. In the docs you are shown:
$order = Order::first();
# direct access to users
print_r($order->users); # will print an array of User object
Which you are already doing via Contact::find(1234)->prefs. Let me boil it down a bit
$contact = Contact::find(1234);
# direct access to prefs
print_r($contact->prefs); # will print an array of ContactPref object
Second, what you actually want is undefined. What should Contact::find(1234)->preference actually do? Return the preference of the first ContactPref? Return an array of Preference objects?
I feel like offering both:
<?php
class Contact extends ActiveRecord\Model {
static $primary_key = 'contactID';
static $has_many = array(
array(
'prefs',
'foreign_key' => 'contactid',
'primary_key' => 'contactid',
'class_name' => 'ContactPref'
),
array(
'preferences',
'foreign_key' => 'prefid',
'primary_key' => 'prefid',
'through' => 'prefs',
'class_name' => 'Preference'
)
);
public function get_preference() {
return isset($this->prefs[0])
? $this->prefs[0]->preference
: null
;
}
public function get_preferences() {
$preference=array();
foreach($this->prefs as $pref) {
$preference[]=$pref;
}
return $preference;
}
}
Let me explain a little bit what I have done. The ActiveRecord\Model class has a __get($name) function that looks for another function called get_$name, where $name in your case is preference (for the first result) and preference (for the entire collection). This means you can do Contact::find(1234)->preference which would be the same as doing Contact::find(1234)->prefs[0]->preference (but safer, due to the check) and Contact::find(1234)->preferences to get the entire collection of preferences.
This can be made better or optimized in numerous ways, so please don't take it as it is, but do try and adapt it to your specific situation.
For example you can either use the id of the preference as an index in the array or either not force a load of more data from ContactPrefs than the ones you are going to use and try a more intricate query to get the preference objects that you specifically need.
If I find a better implementation by getting through to work in the relationship definition, I'll return. But seeing the Unit Tests for active record, I'm skeptical.
There are several things that look strange, so it's not easy to come to a "this will fix it" for you, but this is an issue at least:
Fieldnames should always be lower-case in phpactiverecord. SQL doesn't mind it either way (not that table names ARE case-sensitive, but column names aren't). So make this:
static $primary_key = 'contactID';
into
static $primary_key = 'contactid';
The connections // find commands can be used in SQL, in which case it doesn't really matter how your key-string is 'cased', so some stuff works. But if the connection goes trough the inner-workings of phpmyadmin, it will fail. So check out this contactID but also the prefID.
Again, this goes only for COLUMN names, so don't go changing classnames or table-names to lowercase.
(extra point: phpmyadmin has trouble with combined primary keys. So while it might be ugly, you could add an extra row to your contactprefs table (if you don't allready have it) called id, to make that table actually have something to work with. It wouldn't give you much trouble, and it would help the activerecord library a lot)
Try the following:
<?php
var_dump(Contact::find(1234)->preferences);
The documentation says that with a has_many relationship, it should be referenced by a plural (http://www.phpactiverecord.org/projects/main/wiki/Associations#has_many_through). The Contact::find(1234) returns a Contact object which has multiple contactPrefs with their each Preference. In addition, in your Contact model, you specify the has_many as preferences .
static $has_many = array(
array(
'prefs',
'foreign_key' => 'contactid',
'primary_key' => 'contactid',
'class_name' => 'ContactPref'
),
array(
'preferences',
'foreign_key' => 'prefid',
'primary_key' => 'prefid',
'through' => 'prefs',
'class_name' => 'Preference'
)
);
Edit Through Modification:
Try the following Contact model
<?php
class Contact extends ActiveRecord\Model {
static $primary_key = 'contactID';
static $has_many = array(
array(
'prefs',
'foreign_key' => 'contactid',
'class_name' => 'ContactPref'
),
array('preferences',
'through' => 'prefs',
'class_name' => 'Preference',
'primary_key' => 'prefID')
);
}