问题描述

我为这个可怕的标题道歉，我想不出如何解释我的问题.

I apologize for the horrible title, I couldn't think of how to explain my problem.

在我的数据库中，我有以下表格:articles、tags 和 articles_tags.一篇文章可以有多个标签.

In my database I have the following tables, articles, tags, and articles_tags. An article can have many tags.

目前我能够抓取所有带有所有标签的文章，但我希望能够根据它的标签找到文章.

Currently I am able to grab all the articles, with all the tags, but I want to be able to find articles based upon it's tags.

我的选择很简单:

$articles = $this->Article->find('all', array(
    // extra condition to check for tag, maybe?
    'conditions'    => array('Article.status' => 'active'), 
    'limit'         => $this->articles_per_page,
    'offset'        => ($page_num-1)*$this->articles_per_page
));

我从数据库返回如下:

Array
(
[0] => Array
    (
        [Article] => Array
            (
                [id] => 1
            )

        [Tag] => Array
            (
                [0] => Array
                    (
                        [id] => 1
                        [name] => Ruby
                        [slug] => ruby
                        [uses] => 1
                        [ArticlesTag] => Array
                            (
                                [id] => 1
                                [article_id] => 1
                                [tag_id] => 1
                            )

                    )

            )

    )

如果我只想返回带有 Ruby 标签的文章怎么办?

What do I do if I only want to return the articles with a Ruby tag?

推荐答案

试试这个

// In your Article model
function getArticleByTagSql($tag)
{       
        $dbo = $this->getDataSource();
        $subQuery = $dbo->buildStatement(
        array(
                    'fields' => array('DISTINCT(ArticlesTag.article_id)'),
                    'table' => "articles_tags",                                    
                    'joins' => array(
                                array('table' => 'tags',
                                    'alias' => 'Tag',
                                    'type' => 'INNER',
                                    'conditions' => array('ArticlesTag.tag_id = Tag.id')
                                    )
                                ),
                    'alias'=>"ArticlesTag",                                         
                    'conditions' => array("Tag.name"=>Sanitize::clean($tag_words)),
                    'order' => null,
                    'group' => "ArticlesTag.article_id"
                    ),
                    $this
                    );
                    $subQuery = ' Article.id  IN (' . $subQuery . ')';
                    return $dbo->expression($subQuery);

}

// In your Articles Controller

$this->paginate['conditions'][] = $this->Article->getArticleByTagSql($tag_name);
$this->paginate['conditions'][] = array('Article.status' => 'active');
$this->paginate['limit'] = $this->articles_per_page;



// or as per your example
$articles = $this->Article->find('all', array(
                // extra condition to check for tag, maybe?
                'conditions'    => array('Article.status' => 'active',$this->Article->getArticleByTagSql($tag_name)), 
                'limit'         => $this->articles_per_page,
                'offset'        => ($page_num-1)*$this->articles_per_page
            ));

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