mybatis: 多对一通过注解查询数据

多对一通过注解查询数据

案例:获取所有的产品信息和所属分类名

1.实体类:

public class Product {
    private int id;
    private String name;
    private float price;
    private Category category ;
}

 
public class Category {
    private int id;
    private String name;
    private List<Product> products;
}

 

2.dao层:

public interface ProductMapper {

    @Select(" select * from product_ ")
    @Results({ 
　　　　　//column=参数
        @Result(property="category",column="cid",one=@One(select="com.mapper.CategoryMapper.get")) 
    })
    public List<Product> list();
}

public interface CategoryMapper {

    @Select(" select * from category_ where id = #{id}")
    public Category get(int id);
     
}

 

3.测试效果图: