[英]Accessing more than one model deep relationships in Lithium
Is it possible to access more than one model deep in a relationship in Lithium? 是否可以在Lithium的关系中访问多个模型?
For example, I have a User model: 例如,我有一个用户模型:
class Users extends \lithium\data\Model {
public $validates = array();
public $belongsTo = array("City");
}
and I have a City model: 我有一个城市模型:
class Cities extends \lithium\data\Model {
public $validates = array();
public $belongsTo = array("State");
}
and a State model, and so on. 和国家模型,等等。
If I'm querying for a User, with something similar to Users::first()
, is it possible to get all the relationships included with the results? 如果我正在查询用户,使用类似于
Users::first()
,是否可以获得结果中包含的所有关系? I know I can do Users::first(array('with' => 'City'))
but I'd like to have each City return its State model, too, so I can access it like this: 我知道我可以做
Users::first(array('with' => 'City'))
但是我想让每个City都返回它的State模型,所以我可以像这样访问它:
$user->city->state->field
Right now I can only get it to go one deep ( $user->city
) and I'd have to requery again, which seems inefficient. 现在我只能让它深入(
$user->city
)并且我必须再次重新查询,这似乎效率低下。
Using a recent master you can use the following nested notation: 使用最近的master,您可以使用以下嵌套表示法:
Users::all( array(
'with' => array(
'Cities.States'
)
));
It will do the JOINs for you. 它会为你做JOIN。
I am guessing you are using SQL? 我猜你在使用SQL?
Lithium is mainly designed for noSQL db´s, so recursiveness / multi joins are not a design goal. Lithium主要是为noSQL db而设计的,因此递归/多连接不是设计目标。
Think about the quotient of n Cities to m States. 想想n个城市对m个国家的商数。 => fetch the user with city and then the state by the state id.
=>使用city获取用户,然后按州id获取状态。 => pass that as two keys or embed the state info.
=>将其作为两个键传递或嵌入状态信息。 This would be acceptable for Users::all() queries aswell.
这对于Users :: all()查询也是可以接受的。
Example using Lithiums util\\Set Class: 使用Lithiums util \\ Set类的示例:
use \lithium\util\Set;
$users = Users::all(..conditions..);
$state_ids = array_flip(array_flip(Set::extract($users->data(), '/city/state_id')));
$stateList = States::find('list',array(
'conditions' => array(
'id' => $state_ids
),
));
You can set up relationships in this way, but you have to use a more verbose relationship definition. 您可以通过这种方式设置关系,但必须使用更详细的关系定义。 Have a look at the data that gets passed when constructing a Relationship for details about the options you can use.
查看构建关系时传递的数据,以获取有关可以使用的选项的详细信息。
class Users extends \lithium\data\Model {
public $belongsTo = array(
"Cities" => array(
"to" => "app\models\Cities",
"key" => "city_id",
),
"States" => array(
"from" => "app\models\Cities",
"to" => "app\models\States",
"key" => array(
"state_id" => "id", // field in "from" model => field in "to" model
),
),
);
}
class Cities extends \lithium\data\Model {
public $belongsTo = array(
"States" => array(
"to" => "app\models\States",
"key" => "state_id",
),
);
}
class States extends \lithium\data\Model {
protected $_meta = array(
'key' => 'id', // notice that this matches the value
// in the key in the Users.States relationship
);
}
When using the States relationship on Users, be sure to always include the Cities relationship in the same query. 在用户上使用States关系时,请务必始终在同一查询中包含Cities关系。 For example:
例如:
Users::all( array(
'with' => array(
'Cities',
'States'
)
) );
I have never tried this using belongsTo relationships, but I have it working using hasMany relationships in the same way. 我从来没有尝试过使用belongsTo关系,但我让它以同样的方式使用hasMany关系。
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