Hibernate让Model支持关联扩展属性：
select new Jxc(a,b.mc) from Jxc as a,btb as b
在Model中创建构造方法:
Jxc(Jxc jxc ,String mc){
BeanUtilsBean.getInstance().copyProperties(this, jxc);
this.setMc(mc);
}
给Model设备transient属性：
@Transient
public String getMc() {
return mc;
}
public void setMc(String value) {
this.mc = value;
}
