使用Symfony2和Doctrine 2从数据库加载大数据 [英] Loading large data from database with Symfony2 and Doctrine 2
问题描述
我是Symfony2的初学者。
I'm beginner on Symfony2.
我有一个Regions-Countries-States-Cities数据库,有超过2,000,000个结果。我有8个实体:
I have a Regions-Countries-States-Cities database with more of 2,000,000 results. I have 8 entities:
Region (recursive with itself) - RegionTranslation
Country - CountryTranslation
State (recursive with itself) - StateTranslation
City - CityTranslation
我想加载一个国家列表(例如在一个下拉列表中只有250个寄存器)Symfony + Doctrine加载所有实体结构(所有国家的所有状态,所有州的所有城市及其各自的翻译)。
The thing is that when I want to load a countries list (only 250 registers in a pulldown, for example) Symfony+Doctrine load all entities structure (all states of all countries, and all cities of all states, with their respective translations).
我认为它需要很多内存。
I think that it spends a lot of memory.
这是正确的方法是什么?我可以只加载这个结构的国家(和翻译)吗?任何想法?
What's the correct method to do it? Can I load only Country (and translations) with this structure? Any idea?
推荐答案
我有同样的问题,最好的办法是使用select2的ajax加载( http://ivaynberg.github.com/select2/ ) ),这将在搜索框中提供有限数量的项目,还可以根据框中键入的内容进行窄搜索。
I have had the same problem for objected that are unassociated. Your best bet is to use select2's ajax loading (http://ivaynberg.github.com/select2/), which will give a limited number of items in the search box, and also narrow searches down by what is typed in the box.
有些事情需要编码:
一个javascript文件:
A javascript file:
$(document).ready(function(){
$('.select2thing').select2({
minimumInputLength:1
,width: "100%"
,ajax: {
url: <<path>> + "entity/json"
,dataType: 'jsonp'
,quitMillis: 100
,data: function (term, page) {
return {
q: term, // search term
limit: 20,
page: page
};
}
,results: function (data, page) {
var more = (page * 20) < data.total;
return { results: data.objects, more: more };
}
}
});
}
控制器中的jsonAction:
A jsonAction in the controller:
/**
* Lists all Thing entities return in json format
*
*/
public function jsonAction(Request $request)
{
$em = $this->getDoctrine()->getManager();
$rep = $em->getRepository('yourBundle:Thing');
$qb = $rep->createQueryBuilder('e');
$limit = $request->query->get('limit');
$current = $request->query->get('current');
$page=$request->query->get('page');
$queries=$request->query->get('q');
$qarray=explode(",", $queries);
$entities=$rep->getJSON($qarray, $page, $limit);
$total=$rep->getJSONCount($qarray);
$callback=$request->query->get('callback');
return $this->render('yourBundle:Thing:json.html.twig'
, array(
'entities' => $entities
,'callback' => $callback
,'total' => $total
)
);
}
树枝模板(json.html.twig,
A twig template (json.html.twig, possibly customized to display more)
{{callback}}(
{ "objects" :
[
{% for entity in entities %}
{ "id": "{{entity.id}}", "text": "{{entity}}""}
{% if not loop.last %},{% endif %}
{% endfor %}
],
"total": {{total}}
}
)
变压器:
use Symfony\Component\Form\DataTransformerInterface;
use Symfony\Component\Form\Exception\TransformationFailedException;
use Doctrine\Common\Persistence\ObjectManager;
use yourBundle\Entity\Thing;
class ThingTransformer implements DataTransformerInterface
{
/**
* @var ObjectManager
*/
private $em;
/**
* @param ObjectManager $em
*/
public function __construct(ObjectManager $em)
{
$this->em = $em;
}
/**
* Transforms an object (thing) to a string (id).
*
* @param Issue|null $thing
* @return string
*/
public function transform($thing)
{
if (null === $thing) {return "";}
if (is_object($thing) && "Doctrine\ORM\PersistentCollection"==get_class($thing)){
$entity->map(function ($ob){return $ob->getId();});
return implode(",",$thing->toArray());
}
return $thing;
}
/**
* Transforms a string (id) to an object (thing).
*
* @param string $id
* @return Issue|null
* @throws TransformationFailedException if object (thing) is not found.
*/
public function reverseTransform($id)
{
if (!$id) {
return null;
}
//if (is_array($id)){
$qb=$this->em
->getRepository('yourBundle:Thing')
->createQueryBuilder('t');
$thing=$qb->andWhere($qb->expr()->in('t.id', $id))->getQuery()->getResult();
if (null === $entity) {
throw new TransformationFailedException(sprintf(
'A thing with id "%s" does not exist!',
$id
));
}
return $thing;
}
}
您的控制器使用select2控件将必须通过'em'to the form builder:
Your Controller using the select2 control will have to pass the 'em' to the form builder:
$editForm = $this->createForm(new ThingType()
,$entity
,array(
'attr' => array(
'securitycontext' => $sc
,'em' => $this->getDoctrine()
->getEntityManager()
)
)
);
在您的表单类型中:
if (isset($options['attr']['em'])){ $em = $options['attr']['em'];} else {$em=null;}
$transformer = new ThingTransformer($em);
$builder->add(
$builder->create('thing'
,'hidden'
,array(
'by_reference' => false
,'required' => false
,'attr' => array(
'class' => 'select2thing'
)
)
)
->prependNormTransformer($transformer)
);
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