text: use testbugucms;
  create table middles
  (
    id   int auto_increment comment '主键ID'
      primary key,
    p_id int not null comment '父级属性ID',
    m_id int not null comment '属性ID'
  )
    comment '文章属性关联表';
  
  INSERT INTO testbugucms.middles (id, p_id, m_id) VALUES (1, 1, 1);
  INSERT INTO testbugucms.middles (id, p_id, m_id) VALUES (2, 1, 2);