How to select count with Laravel's fluent query builder?

问题

Here is my query using fluent query builder.

    $query = DB::table('category_issue')
        ->select('issues.*')
        ->where('category_id', '=', 1)
        ->join('issues', 'category_issue.issue_id', '=', 'issues.id')
        ->left_join('issue_subscriptions', 'issues.id', '=', 'issue_subscriptions.issue_id')
        ->group_by('issues.id')
        ->order_by(DB::raw('COUNT(issue_subscriptions.issue_id)'), 'desc')
        ->get();

As you can see, I am ordering by a count from the joined table. This is working fine. However, I want this count returned with my selections.

Here is the my raw sequel query that works fine.

Select issues.*, COUNT(issue_subscriptions.issue_id) AS followers 
FROM category_issue JOIN Issues ON category_issue.issue_id = issues.id 
LEFT JOIN issue_subscriptions ON issues.id = issue_subscriptions.issue_id
WHERE category_issue.category_id = 1
GROUP BY issues.id
ORDER BY followers DESC

How would I go about this select using Laravel's fluent query builder? I am aware I can use a raw sql query but I would like to avoid that if possible. Any help would be appreciated, thanks in advance!

回答1:

You can use an array in the select() to define more columns and you can use the DB::raw() there with aliasing it to followers. Should look like this:

$query = DB::table('category_issue')
    ->select(array('issues.*', DB::raw('COUNT(issue_subscriptions.issue_id) as followers')))
    ->where('category_id', '=', 1)
    ->join('issues', 'category_issue.issue_id', '=', 'issues.id')
    ->left_join('issue_subscriptions', 'issues.id', '=', 'issue_subscriptions.issue_id')
    ->group_by('issues.id')
    ->order_by('followers', 'desc')
    ->get();

回答2:

$count = DB::table('category_issue')->count();

will give you the number of items.

For more detailed information check Fluent Query Builder section in beautiful Laravel Documentation.

来源：https://stackoverflow.com/questions/13223512/how-to-select-count-with-laravels-fluent-query-builder