在tp5两表联合查询中进行搜索，并解决（字段）不明确

在tp5两表联合查询中进行搜索，并解决（字段）不明确

    public function adc()
    {
        $where = [];
        if (input('?ok')) {
            $ok = input('ok');
            $where['a.name'] = ['like', "%$ok%"];
        }
        // 分页
        $list = db('shanpin')->alias('a')
            ->where($where)
            ->order('id', 'desc')
            ->field('a.*,u.id as yid,u.name as uname')
            ->join('fenlie u', 'u.id = a.fenid')
            ->paginate(8, false, ['query' => request()->param()]);
        $a = $list->items();
        $this->assign('list', $a);
        $pag = $list->render();       
        $this->assign('pag', $pag);
        return $this->fetch();
    }

html中的name值

                <form action="" method="POST">
                  <div class="layui-form-mid">用户名:</div>
                  <div class="layui-input-inline" style="width: 100px;">
                    <input type="text" autocomplete="off" class="layui-input" name="ok">
                  </div>
                  <button class="layui-btn layui-btn-blue" type="submit">查询</button>
                  <button class="layui-btn layui-btn-primary">重置</button>
                </form>