think\Model::db PHP Method

    public function db($baseQuery = true)
    {
        $model = $this->class;
        if (!isset(self::$links[$model])) {
            // 设置当前模型 确保查询返回模型对象
            $query = Db::connect($this->connection)->model($model, $this->query);
            // 设置当前数据表和模型名
            if (!empty($this->table)) {
                $query->setTable($this->table);
            } else {
                $query->name($this->name);
            }
            if (!empty($this->pk)) {
                $query->pk($this->pk);
            }
            self::$links[$model] = $query;
        }
        // 全局作用域
        if ($baseQuery && method_exists($this, 'base')) {
            call_user_func_array([$this, 'base'], [&self::$links[$model]]);
        }
        // 返回当前模型的数据库查询对象
        return self::$links[$model];
    }

 private function sql()
 {
     //迁移数据
     //初始化Model
     $connection_new = array('DB_TYPE' => 'mysql', 'DB_HOST' => 'localhost', 'DB_NAME' => 'web_association', 'DB_USER' => 'root', 'DB_PWD' => '', 'DB_PORT' => 3306, 'DB_PREFIX' => 'wa_', 'db_charset' => 'utf8');
     $connection_old = array('DB_TYPE' => 'mysql', 'DB_HOST' => 'localhost', 'DB_NAME' => 'association', 'DB_USER' => 'root', 'DB_PWD' => '', 'DB_PORT' => 3306, 'DB_PREFIX' => '', 'db_charset' => 'utf8');
     $new_mo = new Model();
     $new_mo->db(null, $connection_new);
     $old_mo = new Model();
     $old_mo->db(null, $connection_old);
     /*/数据迁移userinf_login
     		$old_mo->table('userinf_login');
     		$all_user=$old_mo->select();
     		$abc_time=array(
     			'A'=>'2014-12-10 23:33:33',
     			'B'=>'2015-03-30 23:33:33',
     			'C'=>'2015-09-01 23:33:33',
     		);
     		$data=array();
     		for ($i = 0; $i < count($all_user); $i++) {
     			//赋值users表
     			preg_match('/^\w/', $all_user[$i]['id_formal'],$reStr);
     			$data['uid']		=$all_user[$i]['id_formal'];
     			$data['qq']			=$all_user[$i]['id_person'];
     			$data['password']	=$all_user[$i]['password'];
     			$data['date']		=$abc_time[$reStr[0]];
     			$new_mo->table('__USERS__');
     			$new_mo->add($data,null,true);
     			//赋值token表
     			$new_mo->table('__TOKEN__');
     			$new_mo->add(array('uid'=>$all_user[$i]['id_formal'],'token'=>get_rand_char(20)),null,true);
     		}
     		//数据迁移userinf_basic
     		$old_mo->table('userinf_basic');
     		$all_basic=$old_mo->select();
     		for ($i = 0; $i < count($all_basic); $i++) {
     			//填充__USER_INF__
     			$data1=array();
     			$data1['uid']		= $all_basic[$i]['id_formal'];
     			$data1['name']		= $all_basic[$i]['name'];
     			$data1['gender']	= $all_basic[$i]['sex'];
     			$data1['age']		= $all_basic[$i]['old'];
     			$data1['phone']		= $all_basic[$i]['phone'];
     			$data1['school']	= $all_basic[$i]['school'];
     			$data1['wechat']	= $all_basic[$i]['wechat'];
     			$new_mo->table('__USER_INF__')->add($data1,null,true);
     			//填充__NUTS__
     			$data2=array();
     			$data2['uid']			= $all_basic[$i]['id_formal'];
     			$data2['cumulative']	= $all_basic[$i]['integral_cumulative'];
     			$data2['nuts']			= $all_basic[$i]['integral_surplus'];
     			$new_mo->table('__NUTS__')->add($data2,null,true);
     		};
     		//数据迁移userinf_active
     		$old_mo->table('userinf_active');
     		$all_active=$old_mo->select();
     		for ($i = 0; $i < count($all_active); $i++) {
     			//填充__INVITE_CODE__
     			$new_mo->table('__INVITE_CODE__');
     			$data['invite_code']	=$all_active[$i]['active'];
     			$data['date']			=$all_active[$i]['date'];
     			$data['uid']			=$all_active[$i]['user'];
     			$new_mo->add($data);
     		}
     		//更新时间
     		$userMo=new UsersModel();
     		$codeMo=new InviteCodeModel();
     		$allUser=$userMo->field('date,uid')->select();
     		var_dump($allUser);
     		for ($i=0;$i<\count($allUser);$i++){
     			$codeMo->where(array('uid'=>$allUser[$i]['uid']));
     			$codeMo->data(array('date'=>$allUser[$i]['date']));
     			$userMo->save();
     		}
     		//*/
 }