laravel DB 连接查询取别名出错了，table不存在

<code>DB::table('topics')->select('topics.*', 'b.username',
            'b.avatar', 'c.username as rname', 'd.cname')
            ->where('topics.is_hidden', 0)
            ->leftJoin('users b', 'b.uid', '=', 'topics.uid')
            ->leftJoin('users c', 'c.uid', '=', 'topics.ruid')
            ->leftJoin('nodes d', 'd.node_id', '=', 'topics.node_id')
            ->orderBy('ord', 'desc')
            ->take($limit)->get();
</code>

连接查询取别名出错了
SQLSTATE[42S02]: Base table or view not found: 1146 Table 'startbbs.stb_users b' doesn't exist (SQL: select stb_topics.*, stb_b.username, stb_b.avatar, stb_c.username as rname, stb_d.cname from stb_topics left join stb_users b on stb_b.uid = stb_topics.uid left join stb_users c on stb_c.uid = stb_topics.ruid left join stb_nodes d on stb_d.node_id = stb_topics.node_id where stb_topics.is_hidden = 0 order by ord desc limit 20)

回复内容：

<code>DB::table('topics')->select('topics.*', 'b.username',
            'b.avatar', 'c.username as rname', 'd.cname')
            ->where('topics.is_hidden', 0)
            ->leftJoin('users b', 'b.uid', '=', 'topics.uid')
            ->leftJoin('users c', 'c.uid', '=', 'topics.ruid')
            ->leftJoin('nodes d', 'd.node_id', '=', 'topics.node_id')
            ->orderBy('ord', 'desc')
            ->take($limit)->get();
</code>

连接查询取别名出错了
SQLSTATE[42S02]: Base table or view not found: 1146 Table 'startbbs.stb_users b' doesn't exist (SQL: select stb_topics.*, stb_b.username, stb_b.avatar, stb_c.username as rname, stb_d.cname from stb_topics left join stb_users b on stb_b.uid = stb_topics.uid left join stb_users c on stb_c.uid = stb_topics.ruid left join stb_nodes d on stb_d.node_id = stb_topics.node_id where stb_topics.is_hidden = 0 order by ord desc limit 20)

最好的做法是把这SQL复制到数据库管理工具中执行下，看是否是你构造的有问题

从你构造的sql看，是因为别名中加上了表前缀'stb'