How to properly link these articles?

Question

I am trying to link articles with one another. The scenario is define below

Take articles A, B and C.

• Admin links A to B. So, we automatically add links for B to A.
• Admin links B to C. So, we automatically add links for C to B (normal scenario) as well as C to A (because B is linked to A). ( How can i do this? I tried the below code but can't move forward )
• Admin deletes the link from B to C. So, we automatically delete links for C to B as well as C to A.

My code:

 public function executeLinkarticle(sfWebRequest $request) {

        $this->articleId = $request->getParameter('id');
        if ($request->isMethod('POST')) {
            $articles = $request->getParameter('articles');
            $articleId = $request->getParameter('articleId');
            foreach ($articles as $linkedArticleId) {
                //Linking A To B
                $linkedArticleObj =  new BlogArticleLinkedArticle();
                $linkedArticleObj->setArticleId($articleId);
                $linkedArticleObj->setLinkedArticleId($linkedArticleId);
                $linkedArticleObj->save();

                //Linking B To A
                $linkedArticleObj =  new BlogArticleLinkedArticle();
                $linkedArticleObj->setArticleId($linkedArticleId);
                $linkedArticleObj->setLinkedArticleId($articleId);
                $linkedArticleObj->save();

                //linking C to A code
                Checking the Database Table IF B is LINKED WITH A(i.e already linked) THEN how to link C to A ?

            }
            return $this->renderText();
        }
    }

Table Structure

ID   |    ARTICLE_ID  |    LINKED_ARTICLE_ID