学说Querybuilder，关于单向OneToMany和ManyToMany关系的LEFT JOIN

Question

我使用准则2.5，并且在用queryBuilder进行多计数请求时遇到了困难。

MDD

如您所见，AbstractArticle实体与标记为mainTag的标签具有ManyToOne关系，而同一个实体标记为tags的标签具有ManyToMany关系。

我想做什么

我想从标记ID的列表中发出一个请求，以计算主要标记的AbstractArticle和默认标记的AbstractArticle的数量。

这是我想要的回报

+--------+-------------------------+----------------------------+
| TagId  | mainTaggedArticleCount  | defaultTaggedArticleCount  |
+--------+-------------------------+----------------------------+
|      1 |                       2 |                          0 |
|      2 |                       0 |                          5 |
|      3 |                       2 |                          2 |
+--------+-------------------------+----------------------------+

我目前的尝试

我成功完成了以下mySQL请求，得到了我想要的：

SELECT 
tag.id as tagId,
(select count(DISTINCT aaMain.id)) as mainTaggedArticleCount,
(select count(DISTINCT aaDefault.id)) as defaultTaggedArticleCount

FROM tag tag
/* Left join on ManyToOne nammed `mainTag` */
LEFT JOIN abstract_article aaMain ON aaMain.main_tag_id = tag.id
/* Left join on ManyToMany nammed `tags` with the junction table */
LEFT JOIN abstract_article_tag aat ON aat.tag_id = tag.id
LEFT JOIN abstract_article aaDefault ON aaDefault.id = aat.abstract_article_id

where tag.id in (3, 1, 5, 6) /* My list of tag Ids */
group by tag.id

但是在学说上要复杂得多> <...我为这样的OneToMany关系做了左连接：

$qb->leftJoin(AbstractArticle::class,'mainTaggedArticle',Join::WITH,'mainTaggedArticle.mainTag = t.id')

但是它不适用于ManyToMany。因为连接表abstract_article_tag在整个理论中都是不可见的。

对我有什么想法吗？ 在此先感谢：）

Answer 1

我做到了！ 有2个子请求，这是我的解决方案

在我的TagRepository内部

$repoAbastractArticle = $this->getEntityManager()->getRepository("AbstractArticle");

// SubRequest for main tagged article
$countMainTaggedArticleSubQuery = $repoAbstractArticle->createQueryBuilder("abstract_article");
$countMainTaggedArticleSubQuery->select('COUNT(DISTINCT abstract_article.id)')
    ->leftJoin('abstract_article.mainTag', 'mainTag')
    ->andWhere($countMainTaggedArticleSubQuery->expr()->eq('mainTag.id', 'tag.id'));

// SubRequest for tagged article 
$countDefaultTaggedAbstractArticleSubQuery = $repoAbstractArticle->createQueryBuilder("default_tagged_abstract_article");
$countDefaultTaggedAbstractArticleSubQuery->select('COUNT(DISTINCT default_tagged_abstract_article.id)')
    ->leftJoin('default_tagged_abstract_article.tags', 'tags')
    ->andWhere($countDefaultTaggedAbstractArticleSubQuery->expr()->eq('tags.id', 'tag.id'));

// Main request
$qb = $this->createQueryBuilder("tag");
    $qb->select('
    tag.id AS tagId, 
    (' . $countMainTaggedArticleSubQuery . ') AS mainTaggedArticleCount, 
    (' . $countDefaultTaggedAbstractArticleSubQuery . ') AS defaultTaggedArticleCount'
    )
    ->groupBy('tag.id')
    ->andWhere($qb->expr()->in('tag.id', ':tagIds'))
    ->setParameter('tagIds', $tagIds);

return $qb->getQuery()->getResult();