<resultMap type="Teachers" id="testResultMap">
<id column="id" property="ids"/>
<result column="name" property="names"/>
</resultMap>
<select id="testResultMap" resultMap="testResultMap" >
select * from teacher
</select>
public class Teachers {
private int ids;
private String names;
使用<resultMap>查询关联集合对象(N+1)
1. 在Teacher 中添加List<Student>
public class Teacher {
private int id;
private String name;
private List<Student>
list;
}
2. 在StudentMapper.xml 中添加通过tid 查询
<select id="selByTid" parameterType="int"
resultType="student">
select * from student where tid=#{0}
</select>
3. 在TeacherMapper.xml 中添加查询全部
<resultMap type="teacher" id="mymap">
<id column="id" property="id"/>
<result column="name" property="name"/>
<collection property="list"
select="com.bjsxt.mapper.StudentMapper.selByTid"
column="id"></collection>
</resultMap>
<select id="selAll" resultMap="mymap">
select * from teacher
</select>
转载于:https://www.cnblogs.com/lastingjava/p/9972325.html
