mybatis注解映射的简单分类

转自：https://blog.csdn.net/yalishadaa/article/details/56038992

1、普通映射

    @Select("select * from user where id=#{id}")
    public User getUser(int id);
    @Insert("insert into user(id,name) values (#{id},#{name})")
    public int insert(User user);
    @Update(update user set name=#{name} where id=#{id})
    public int update(User user);
    @Delete("delete from user where id=#{id}")
    public  int delete(int id);

2、结果集映射

    @Select("select * from user")
    @Results({
            @Result(id=true,property =""id,column = "id")
            @Result(property = "name" column="name")
    })
    public List<User> getAllUsers();

3、关系映射

一对一

@Select("select * from mybatis_Student")  
@Results({  
    @Result(id=true,property="id",column="id"),  
    @Result(property="name",column="name"),  
    @Result(property="age",column="age"),  
    @Result(property="address",column="address_id",one=@One(select="com.skymr.mybatis.mappers.AddressMapper.getAddress"))  
})  
public List<Student> getAllStudents();  

一对多

 @Select("select * from mybatis_grade where id=#{id}")  
    @Results({  
        @Result(id=true,column="id",property="id"),  
        @Result(column="grade_name",property="gradeName"),  
        @Result(property="students",column="id",many=@Many(select="com.skymr.mybatis.mappers.Student2Mapper.getStudentsByGradeId"))  
    })  
    public Grade getGrade(int id);