php 如何使用symfony2学说查询构建器选择不同的查询？
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How to select distinct query using symfony2 doctrine query builder?
提问by mickburkejnr
I have this symfony code where it retrieves all the categories related to a blog section on my project:
我有这个 symfony 代码，它检索与我的项目中的博客部分相关的所有类别：
$category = $catrep->createQueryBuilder('cc')
->Where('cc.contenttype = :type')
->setParameter('type', 'blogarticle')
->getQuery();
$categories = $category->getResult();
This works, but the query includes duplicates:
这有效，但查询包含重复项：
Test Content
Business
Test Content
I want to use the DISTINCTcommand in my query. The only examples I have seen require me to write raw SQL. I want to avoid this as much as possible as I am trying to keep all of my code the same so they all use the QueryBuilder feature supplied by Symfony2/Doctrine.
我想DISTINCT在我的查询中使用该命令。我见过的唯一示例要求我编写原始 SQL。我想尽可能避免这种情况，因为我试图保持所有代码相同，以便它们都使用 Symfony2/Doctrine 提供的 QueryBuilder 功能。
I tried adding distinct()to my query like this:
我尝试distinct()像这样添加到我的查询中：
$category = $catrep->createQueryBuilder('cc')
->Where('cc.contenttype = :type')
->setParameter('type', 'blogarticle')
->distinct('cc.categoryid')
->getQuery();
$categories = $category->getResult();
But it results in the following error:
但它导致以下错误：
Fatal error: Call to undefined method Doctrine\ORM\QueryBuilder::distinct()
致命错误：调用未定义的方法 Doctrine\ORM\QueryBuilder::distinct()
How do I tell symfony to select distinct?
我如何告诉 symfony 选择不同的？
采纳答案by Raffael
you could write
你可以写
select DISTINCT f from t;
as
作为
select f from t group by f;
thing is, I am just currently myself getting into Doctrine, so I cannot give you a real answer. but you could as shown above, simulate a distinct with group byand transform that into Doctrine. if you want add further filtering then use HAVINGafter group by.
问题是，我目前刚刚进入 Doctrine，所以我不能给你一个真正的答案。但是您可以如上所示，使用group by模拟一个不同的对象并将其转换为Doctrine。如果你想添加进一步的过滤，那么HAVING在 group by之后使用。
回答by skler
This works:
这有效：
$category = $catrep->createQueryBuilder('cc')
->select('cc.categoryid')
->where('cc.contenttype = :type')
->setParameter('type', 'blogarticle')
->distinct()
->getQuery();
$categories = $category->getResult();
回答by Chris
If you use the "select()" statement, you can do this:
如果您使用“select()”语句，您可以这样做：
$category = $catrep->createQueryBuilder('cc')
->select('DISTINCT cc.contenttype')
->Where('cc.contenttype = :type')
->setParameter('type', 'blogarticle')
->getQuery();
$categories = $category->getResult();
回答by Ali
Just open your repository file and add this new function, then call it inside your controller:
只需打开您的存储库文件并添加这个新函数，然后在您的控制器中调用它：
public function distinctCategories(){
return $this->createQueryBuilder('cc')
->where('cc.contenttype = :type')
->setParameter('type', 'blogarticle')
->groupBy('cc.blogarticle')
->getQuery()
->getResult()
;
}
Then within your controller:
然后在您的控制器中：
public function index(YourRepository $repo)
{
$distinctCategories = $repo->distinctCategories();
return $this->render('your_twig_file.html.twig', [
'distinctCategories' => $distinctCategories
]);
}
Good luck!
祝你好运！
