Mybatis 一对多关联注解

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最近学习mybatis，记录下一对多关联注解。
这里用班级(Classes)和学生(Student)一对多关联，配置如下：
Classes.java

public class Classes {    public int id;    public String name;    public List<Student> studentList;    //getter/setter    }

Student.java

public class Student {    private int id;    private String name;    private Classes classes;    //getter/setter    }

ClassesMapper.java

public interface ClassesMapper {    @Insert("insert into classes (name) values (#{name})")    @Options(useGeneratedKeys=true,keyProperty="id")    public void insertClasses(Classes classes);    @Select("select * from classes where id=#{id}")    @Results({        @Result(id=true,property="id",column="id"),        @Result(property="name",column="name"),        @Result(property="studentList",column="id",javaType=List.class,        many=@Many(select="com.lsj.test.mybatis.annotation.mapper.StudentMapper.selectStudentByClass"))    })    public Classes selectClasses(int id);    @Delete("delete from classes where id=#{id}")    public void deleteClasses(int id);}

StudentMapper.java

public interface StudentMapper {    @Insert("insert into student (name,classes_id) values(#{name},#{classes.id})")    @Options(useGeneratedKeys=true,keyProperty="id")    public void insertStudent(Student student);    @Select("select * from student where id=#{id}")    @Results({        @Result(id=true,property="id",column="id"),        @Result(property="name",column="name"),        @Result(property="classes",column="classes_id",javaType=Classes.class,        one=@One(select="com.lsj.test.mybatis.annotation.mapper.ClassesMapper.selectClasses"))    })    public Student selectStudent(int id);    @Select("select * from student where classes_id=#{classId}")    @Results({        @Result(id=true,property="id",column="id"),        @Result(property="name",column="name"),        @Result(property="classes",column="classes_id",javaType=Classes.class,        one=@One(select="com.lsj.test.mybatis.annotation.mapper.ClassesMapper.selectClasses"))    })    public List<Student> selectStudentByClass(int classId);    @Delete("delete from student where id=#{id}")    public void deleteStudent(int id);}

这里StudentMapper中，Student中包含classes对象，是多端，通过

        @Result(property="classes",column="classes_id",javaType=Classes.class,        one=@One(select="com.lsj.test.mybatis.annotation.mapper.ClassesMapper.selectClasses")

把student与classes联系起来，这样查询student时，根据classes_id就可以加上classes查询并加入到student中

在ClassesMapper中查询studentList时，引用了StudentMapper中通过班级Id查询Student的select语句

@Result(property="studentList",column="id",javaType=List.class,        many=@Many(select="com.lsj.test.mybatis.annotation.mapper.StudentMapper.selectStudentByClass")

其中many语句需要在StudentMapper定义一个根据班级id查学生的select语句，上面的Result的many中column必须是班级表的id，把班级id传给select语句作为参数。

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