Laravel分页不适用于group by子句

Question

似乎Laravel分页DEO与group by子句不能正常工作。例如：

            $users = Subject::select(DB::raw('subjects.*, count(user_subjects.id) as total_users'))
            ->join('user_subjects', 'user_subjects.subject_id', '=', 'subjects.id')
            ->whereNull('user_subjects.deleted_at')
            ->groupBy('subjects.id')
            ->orderBy('subjects.updated_at', 'desc')
            ->paginate(25);

产生

            select subjects.*, count(user_subjects.id) as total_users 
            from `subjects` inner join `user_subjects` on `user_subjects`.`subject_id` = `subjects`.`id` 
            where `subjects`.`deleted_at` is null and `user_subjects`.`deleted_at` is null 
            group by `subjects`.`id` 
            order by `subjects`.`updated_at` desc

请注意，查询上没有限制子句。

如果查询中没有group by子句，则工作罚款：

$users = Subject::select(DB::raw('subjects.*, count(user_subjects.id) as total_users'))
            ->join('user_subjects', 'user_subjects.subject_id', '=', 'subjects.id')
            ->whereNull('user_subjects.deleted_at')
            ->orderBy('subjects.updated_at', 'desc')
            ->paginate(25);

产生了以下查询：

select subjects.*, count(user_subjects.id) as total_users from `subjects` 
            inner join `user_subjects` on `user_subjects`.`subject_id` = `subjects`.`id`
            where `subjects`.`deleted_at` is null and `user_subjects`.`deleted_at` is null 
            order by `subjects`.`updated_at` desc 
            limit 25 offset 0

有人知道我该怎么解决这个问题吗？

Answer 1

这在laravel 5.2中对我有用

Select(\DB::RAW("assignment_descendant_child.assignment_descendant_child_id, assignment_descendant_child.assignment_descendant_child_name, COUNT(assignment_descendant.assignment_descendant_id) as xNum"))
            ->leftJoin(
                'assignment_descendant',
                'assignment_descendant.assignment_descendant_child_id',
                '=',
                'assignment_descendant_child.assignment_descendant_child_id'
            )
            ->orderBy('assignment_descendant_child_name')
            ->groupBy('assignment_descendant_child.assignment_descendant_child_id')
            ->paginate(\Config::get('constants.paginate_org_index'))

Answer 2

我知道这是一个老问题，因为我正在分享我的解决方案供将来参考。

我设法基于这个链接编写了一个函数，它完成了确定复杂查询分页的繁重工作。只需传递'QueryBuilder'，它将返回分页对象/集合。

此外，此过程可以跟踪和维护除page=之外的其他参数。

public function mergeQueryPaginate(\Illuminate\Database\Eloquent\Builder $query): \Illuminate\Pagination\LengthAwarePaginator
    {
        $raw_query = $query;
        $totalCount = $raw_query->get()->count();

        $perPage = request('per-page', 10);
        $page = request('page', 1);
        $skip = $perPage * ($page - 1);
        $raw_query = $raw_query->take($perPage)->skip($skip);

        $parameters = request()->getQueryString();
        $parameters = preg_replace('/&page(=[^&]*)?|^page(=[^&]*)?&?/', '', $parameters);
        $path = url(request()->getPathInfo() . '?' . $parameters);

        $rows = $raw_query->get();

        $paginator = new LengthAwarePaginator($rows, $totalCount, $perPage, $page);
        $paginator = $paginator->withPath($path);
        return $paginator;
    }

Answer 3

检查留档https://laravel.com/docs/5.2/pagination

目前，Laravel无法有效执行使用groupBy语句的分页操作。如果需要对分页结果集使用groupBy，建议您查询数据库并手动创建分页器。