如何使用eloquent或查询生成器连接两个表 - how to join two tables using eloquent or query builder

how to join two tables using eloquent or query builder

我有这个查询，它基本上列出了两个用户共有的主题。

$subcommon= SubjectUser::selectRaw('topic_id, count(topic_id) AS aggregate')
     ->whereIn('user_id', [4, 2])->groupBy('topic_id')
     ->having('aggregate','>',1)->get();

例如，下面表的查询结果将是

{"topic_id":3,"aggregate":1}

tableone

id|user_id|topic_id
 1|2      |3
 2|4      |3
 3|5      |1

我有另一个表(table2)，也有topic_id，我想加入，以便我从第二个表中获得第2行的查询结果。我该怎么做呢?

tabletwo

id|group_id|topic_id
 1|6      |2
 2|7      |3
 3|7      |1

DB::table('tableone')->join('tabletwo', function($join) {
    $join->on(tableone.topic_id, '=', tabletwo.topic_id);
})->get();

try this，

$subcommon= DB::table('tableone')
     ->selectRaw('topic_id, count(topic_id) AS aggregate')
     ->join('tabletwo','tabletwo.topic_id', '=', 'tableone.topic_id')
     ->whereIn('user_id', [4, 2])
     ->groupBy('tableone.topic_id')
     ->having('aggregate','>',1)
     ->get();