I'm using Solr 9.4.1, with Solarium 6.3.5. Reading through the docs I think I'm coding the implementation correctly, but my documents are not created in Solr as a parent/child relationship. Does it not work that way, and I need to change my search criteria to work with a flat array? I do see in Solr, all records have a root key, and in the case of a parent record it matches its own id, while child records match their parent. But that's the only reference telling me this worked.
Here's my code, hopefully someone that understands Solr/Solarium better than I can see the issue.
public function syncForum()
{
$client = $this->solrclient;
$update = $client->createUpdate();
$db = db_connect();
// Create arrays to store topic and comment documents
$topicQuery = $db->query("SELECT
forum_topics.id AS topic_id,
forum_topics.topic_subject AS topic_subject,
forum_topics.topic_message AS topic_message,
forum_topics.created_at AS created_at,
forum_categories.title AS forum_category,
users.username AS topic_author
FROM
forum_topics
INNER JOIN forum_posts ON forum_posts.post_topic = forum_topics.id
LEFT JOIN users ON users.id = forum_posts.post_by
LEFT JOIN forum_categories ON forum_categories.id = forum_topics.topic_cat");
$topicResult = $topicQuery->getResultArray();
$documentArray = [];
foreach ($topicResult as &$topic) {
//Loop through topics and create a topic document
$document = $update->createDocument();
$document->id = $topic['topic_id'];
$document->topic_subject = $topic['topic_subject'];
$document->topic_message = $topic['topic_message'];
$document->category = $topic['forum_category'];
$document->author = $topic['topic_author'];
// $document->_root_ = 'true';
$topicDate = $topic['created_at'];
$dateTime = new \DateTime($topicDate);
$document->created_at = $dateTime->format("Y-m-d\TH:i:s\Z");
$documentArray[] = $document;
//For each topic, loop through the comments and create a comment document
$commentQuery = $db->query("SELECT forum_posts.id, forum_posts.post_content AS comment_message, forum_posts.created_at, users.username AS author
FROM forum_posts
LEFT JOIN users ON users.id = forum_posts.post_by
WHERE post_topic =" . $topic['topic_id']);
$comments = $commentQuery->getResultArray();
$commArray = [];
foreach ($comments as $i => $comment) {
$commArray[$i]['id'] = $comment['id'];
$commArray[$i]['comment_message'] = $comment['comment_message'];
$commArray[$i]['author'] = $comment['author'];
$originalDate = $comment['created_at'];
$dateTime = new \DateTime($originalDate);
$formattedDate = $dateTime->format("Y-m-d\TH:i:s\Z");
$commArray[$i]['created_at'] = $formattedDate;
}
$document->childdocs = $commArray;
}
// add the documents and a commit command to the update query
$update->addDocuments($documentArray);
$update->addCommit();
// this executes the query and returns the result
$result = $client->update($update);
// Output status information
echo "Status: " . $result->getStatus() . " | Query Time: " . $result->getQueryTime() . PHP_EOL;
}
Note the field you are using childdocs is a "pseudo-field" (ie. not an actual field in the documents), and thus, by default, the matching documents of a search query won't include any of their nested children in the response.
To enrich results with the documents' descendants you need to use the Child Doc Transformer by adding [child] to the field list parameter, eg. fl=*,[child]. You might also need to add the _nest_path_ field to the schema (for the transformer) to enable more features.