mybatis association 如何在一对多查询出多的数据?

Question

老师表 teacher

id	name	age
1	王老师	25
2	李老师	32
3	张老师	23

学生表 student

id	t_id	name	age
1	1	张敏	8
2	1	安仨	7
3	2	胡嗄	8
4	2	历海	8
5	3	萨德	9

<resultMap id="ResultMap" type="org.demo.Teacher">
    <result column="id" property="id" />
    <result column="name" property="name" />
    <result column="age" property="age" />
    <association property="student" columnPrefix="stu_" resultMap="studentResultMap"/>
</resultMap>

<resultMap id="studentResultMap" type="org.demo.Student">
    <result column="id" property="id" />
    <result column="name" property="name" />
    <result column="age" property="age" />
</resultMap>

SELECT
    tc.*,
    st.id AS stu_id,
    st.NAME AS stu_name 
FROM
    teacher tc
    INNER JOIN student st ON tc.id = st.t_id

sql查询出有五条
用resultMap association 查出只有三条数据

Answer 1

teacher里面应该是个list，而不是个bean