CakePHP containable HABTM limit - cakephp

According to the second sentence on the Containable Behavior section of the Cookbook, contain() supports the limit clause.
A new addition to the CakePHP 1.2 core is the ContainableBehavior. This model behavior allows you to filter and limit model find operations.
I'm Using CakePHP 2.5.
I have two models: Product and Category (HABTM relation).
The relations for Product:
public $hasAndBelongsToMany = array(
'Category' => array(
'className' => 'Category',
'joinTable' => 'categories_products',
'foreignKey' => 'product_id',
'associationForeignKey' => 'category_id',
),
);
The relations for Category:
public $hasAndBelongsToMany = array(
'Product' => array(
'className' => 'Product',
'joinTable' => 'categories_products',
'foreignKey' => 'category_id',
'associationForeignKey' => 'product_id',
),
);
I’m trying do use limit as follows:
$cats = $this->Category->find('all', array(
'fields' => array(
'id',
'parent_id'
),
'contain' => array(
'Product' => array(
'fields' => array(
'id',
'name',
),
'limit' => 3,
'order' => array('created DESC'),
),
),
));
The result is that overall only 3 products are selected. Not 3 product per category. The containable behavior is properly loaded. How do I get 3 products per category?

Unfortunately you cannot use 'limit' on HABTM relationships. For performance reasons, CakePHP builds a single query to fetch all the HABTM records, which are later recursively assigned to the parent record key in the output array.
If you apply a LIMIT clause, it will result in CakePHP only fetching a limited number of associated Products, as you have noticed.
The HABTM section in the Cookbook should probably be amended to remove 'limit' as an option, or clarify its intended use.
See this answer for further information:
CakePHP and HABTM Model Limit Error

Related

CakePHP only get results that have a related model

In my CakePHP 2 project, I have Projects that have many Articles, an Article can belong to many projects (a many-to-many relation).
Now I would like to find all Projects that have an Article.
My current code for getting the Projects is as follows
$projects = $this->Project->find('list', array(
'fields' => array('Project.slug', 'Project.name')
));
I tried adding contain to the query, without results
$projects = $this->Project->find('list', array(
'contain' => array('PressArticles' => array()),
'fields' => array('Project.slug', 'Project.name')
));
How can I modify this so I receive all projects that have an article?
Containing won't help, non-1:1 relations will be retrieved in a separate query, so that won't have any effect on your main query.
You could for example manually create INNER joins with the association's join and target table, that would automatically filter out all projects that have no associated articles, something along the lines of this (I've more or less guessed the names, it's just a quick and dirty example):
$projects = $this->Project->find('list', array(
'fields' => array('Project.slug', 'Project.name'),
'joins' => array(
array(
'table' => 'press_articles_projects',
'alias' => 'PressArticleProject',
'type' => 'INNER',
'conditions' => array(
'PressArticleProject.project_id = Project.id',
),
),
array(
'table' => 'press_articles',
'alias' => 'PressArticle',
'type' => 'INNER',
'conditions' => array(
'PressArticle.id = PressArticleProject.press_article_id',
),
)
),
'group' => 'Project.id'
));
Or if you are using a counter cache, then filtering by the counter would be an option too:
$projects = $this->Project->find('list', array(
'fields' => array('Project.slug', 'Project.name'),
'conditions' => array(
'Project.press_article_count >' => 0
)
));
See also
Cookbook > Models > Associations: Linking Models Together > Joining tables
Cookbook > Models > Associations: Linking Models Together > counterCache - Cache your count()
In your Project model, you can do
public $hasMany = array(
'PressArticle' => array(
'className' => 'PressArticle',
'foreignKey' => 'project_id'
)
);
For more info, check here

Select records which have atleast one hasMany relation row in Cakephp

I'm facing a problem with cakephp associations in Models.
I have to Select records which have atleast one hasMany reation row
Model
class Category extends AppModel
{
public $hasMany = array(
'Product' => array(
'className' => 'Product',
'foreignKey' => 'CategoryId',
)
);
}
Query
$categories = $this->Category->find('all');
I only needed the categories which have atleast one product entry
Categories Like : Shirts, Footwear, Glasses etc
Products like :
Small, medium, large (Shirts)
With Frame, UV protected (Glass)
So, i jus want to get Shirts and Glasses Categories only because for the above example there is no products for Footwear
Use counterCache or joins
Please refer to CakePHP - Find and count how many associated records exist
The most simple way with the best performance would be using a properly indexed counter cache field as shown in the linked answer.
Sice the linked answer is not an exact duplicate with respect to the join, here's some additional info, instead of using HAVING COUNT with the join you'd use a IS NOT NULL condition. Here's an (untested) example:
$this->Category->find('all', array(
'joins' => array(
array(
'table' => 'products',
'alias' => 'Product',
'type' => 'LEFT',
'conditions' => array('Category.id = Product.CategoryId')
)
),
'conditions' => array(
'Product.CategoryId IS NOT NULL'
)
'group' => 'Category.id'
));
Depending on the used DBMS and version you might get better performance using an inner join:
$this->Category->find('all', array(
'joins' => array(
array(
'table' => 'products',
'alias' => 'Product',
'type' => 'INNER',
'conditions' => array('Category.id = Product.CategoryId')
)
),
'group' => 'Category.id'
));

CakePHP conditions for deep associations

I have some deep associations using containable and need to filter back the results. For the sake of this question, let's say we are selling cars and want to narrow the results down by features.
Car hasmany make hasmany model HABTM features
$options = array(
'order' => array('Car.price'),
'contain' => array(
'make',
'model' => array(
'order' => 'Model.name ASC'
),
'features'
)
);
$cars = $this->Car->find('all', $options);
How would I go about excluding all cars that don't have power windows (Features.name != power_windows).
Containable is only suitable for you to specify what models you wanted to include when fetching data, but not limiting the parent model from fetching data at all. One obvious symptom is that sometimes your parent data may have some null contained data.
So to achieve it, I think we should use joins here so you can specify condition:
$options = array(
'order' => array('Car.price'),
'contain' => array(
'make',
'model' => array(
'order' => 'Model.name ASC'
),
'features'
),
'joins' => array(
array(
'table' => 'features',
'alias' => 'Feature',
'type' => 'LEFT',
'conditions' => array(
'Car.id = Feature.car_id'
)
)
),
'conditions' => array(
'Features.name !=' => 'power_windows',
)
);
But one drawback of this is that you might have duplicated Car due to joining. That's a separate issue ;)

Associate different column name to one Model + cakephp

how to get name of (UserTransactionType.name) with Transaction.who_pay_fee_1,2,3 fields.
'user_transaction_type_id' works well but how to get the rest of fields work :(
//Transaction Model
public $belongsTo = array(
'UserTransactionType' => array(
'className' => 'UserTransactionType',
'foreignKey' => 'user_transaction_type_id',
'conditions' => '',
'fields' => '',
'order' => ''
),
//UserTransactionType Model
public $hasMany = array(
'Transaction' => array(
'className' => 'Transaction',
'foreignKey' => 'user_transaction_type_id',
'dependent' => false,
))
This is the sample code for your controller:
$this->UserTransactionType->find('all',array(
'fields' => array('name'),
'contain' => array('Transaction')
)
);
If Models are associated you can specify in 'contain' which of them you want to get in the result.
If you want to have only some fields of related Model, you can determine them after 'Transaction' in 'contain' just like in the regular find() query:
'contain' => array('Transaction' => array('fields' => array('field_1',
'field_2') ))
But in your case, you don't need to specify fields, because by default you get all fields.
So no matter if you define or not fields "who_pay_fee_1,2,3" because if you use 'contain' by default you will get foreing_key - user_transaction_type_id.
I hope it's helpful
For people they like CakePhp :)
in Controller ->
get the list of 'UserTransactionType'
in View ->
after looping trough all the transactions; in Transaction Status column simply load the 'UserTransactionType'array and assign the number of array to $userTransactionTypes.
$userTransactionTypes[$transaction['Who_pay_fee_1']];
To be honest it was straight forward but needed a bit concentration :)

Containable behavior doesn't return deeper model association and selecting fields

I want to limit the fields returned by a deeper association using containable.
My associations:
Game hasMany Review
The paginate and containable code:
$this->paginate = array(
'conditions' => $conditions,
'fields' => array(
'Game.id', 'Game.name',
'Publisher.id', 'Publisher.name'
),
'contain' => array(
'Game' => array(
'Review' => array(
'fields' => array('Review.id', 'ROUND(AVG(Review.score),1)')
)
),
)
);
$games = $this->paginate('Game');
Currently, all of the fields in the Review table are returned. 'ROUND(AVG(Review.score),1)' is never returned. How can I specify what fields I want returned from the Review association?
SQL dumps for two search results using #theJetzah's answer. The first is a search with one game as a result and the second is a search returning three games.
SELECT `Review`.`id`, `Review`.`review_text`, `Review`.`score`, `Review`.`user_id`, `Review`.`game_id`, `Review`.`created`, `Review`.`platform_id`, (ROUND(AVG(`Review`.`score`),1)) AS `Review__average_score` FROM `videogamedb`.`reviews` AS `Review` WHERE `Review`.`game_id` = (55)
SELECT `Review`.`id`, `Review`.`review_text`, `Review`.`score`, `Review`.`user_id`, `Review`.`game_id`, `Review`.`created`, `Review`.`platform_id`, (ROUND(AVG(`Review`.`score`),1)) AS `Review__average_score` FROM `videogamedb`.`reviews` AS `Review` WHERE `Review`.`game_id` IN (55, 56, 57)
Not a full answer, but an attempt to get it working :)
Approach1 (UPDATE: Containable doesn't support 'group by')
First of all, try to add the 'Game' model to the $uses array of your Controller, if it is not included yet, and re-organise the pagination array (as previously suggested by Sam), so that you'll be pagination the Game model itself.
Then, It may help to create a virtual field for the calculated score, but the results of 'Review' need to be grouped, otherwise you'll not be able to calculate the average score.
I'm not able to test this, but it may worth trying
something like this;
public $uses = array(
'Game',
// other models
);
public function myfunction()
{
$this->Game->Review->virtualFields['average_score'] = 'ROUND(AVG(Review.score),1)';
$this->paginate = array(
'Game' => array(
'fields' => array(
'Game.id',
'Game.name',
'Publisher.id',
'Publisher.name'
),
'contain' => array(
'Review' => array(
'fields' => array(
'Review.game_id,
'Review.average_score',
),
'group' => array(
'Review.game_id,
),
)
)
)
);
// Conditions can be passed to paginate,
// that way you can specify 'paginate' at
// one place and don't have to modify it
// to include the conditions
$games = $this->paginate('Game', $conditions);
}
Alternative approach: Using joins and a database-view
Apparently, the Containable behavior doesn't like group-by clauses; See this ticket for more information: Containable behavior does not implement 'group' option
CakePHP allows you to manually specify a join: Joining Tables
To simplify things and to prevent having to add a 'group by' for all fields, create a simple database-view in your database;
CREATE VIEW review_scores AS
SELECT
game_id,
ROUND(AVG(score),1) AS average_score,
COUNT(id) AS total_reviews
FROM
reviews
GROUP BY
game_id;
If you're unfamiliar with this; a database 'view' is basically a 'stored query', which can be accessed as if it was a regular table. See Create View
Then, use a 'manual' join, using the newly created database-view as the source-table. In your case, this will look something like this;
$this->paginate = array(
'Game' => array(
'fields' => array(
'Game.id',
'Game.name',
'Publisher.id',
'Publisher.name',
'ReviewScore.average_score',
'ReviewScore.total_reviews',
),
'joins' => array(
array(
'table' => 'review_scores',
'alias' => 'ReviewScore',
'type' => 'LEFT',
'conditions' => array(
'ReviewScores.game_id = Game.id',
)
)
)
)
);
Hope this helps
I think your array is a configured a little wrong, try:
$this->paginate = array(
'Game' => array(
'conditions' => $conditions,
'fields' => array(
'Game.id', 'Game.name',
'Publisher.id', 'Publisher.name'
),
'contain' => array(
'Review' => array(
'fields' => array('Review.id', 'ROUND(AVG(Review.score),1)')
)
)
)
);
$games = $this->paginate('Game');
As an aside, from personal experience, specifying the fields in a query doesn't always speed it up (certainly for small number of fields), assuming this is the motive for doing so. It does reduce memory occupancy but this is only relative to original size of the record and the number of records returned.

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