查詢返回值是map類型的一條數據
1 首先在接口中寫方法
public interface EmployeeMapper {
//返回一條記錄的map；key就是列名，值就是對應的值
public Map<String, Object> getEmpByIdReturnMap(Integer id);
}
2 在映射文件xml配置方法
<!--public Map<String, Object> getEmpByIdReturnMap(Integer id); -->
<select id="getEmpByIdReturnMap" resultType="map">
select * from tbl_employee where id=#{id}
</select>
3在junit方法里進行測試
@Test
public void test04() throws IOException{
SqlSessionFactory sqlSessionFactory = getSqlSessionFactory();
//1、獲取到的SqlSession不會自動提交數據
SqlSession openSession = sqlSessionFactory.openSession();
try{
EmployeeMapper mapper = openSession.getMapper(EmployeeMapper.class);
Map<String, Object> map = mapper.getEmpByIdReturnMap(1);
System.out.println(map);
String email=(String) map.get("email");
System.out.println(email);
}finally{
openSession.close();
}
}
查詢返回值是map類型的多條數據
1 首先在接口中寫方法
public interface EmployeeMapper {
//多條記錄封裝一個map：Map<Integer,Employee>:鍵是這條記錄的主鍵，值是記錄封裝后的javaBean
//@MapKey:告訴mybatis封裝這個map的時候使用哪個屬性作為map的key
@MapKey("email")
public Map<String, Employee> getEmpByLastNameLikeReturnMap(String email);
}
2 在映射文件xml配置方法
<!--public Map<Integer, Employee> getEmpByLastNameLikeReturnMap(String lastName); -->
<select id="getEmpByLastNameLikeReturnMap" resultType="com.atguigu.mybatis.bean.Employee">
select * from tbl_employee where email like #{email}
</select>
3在junit方法里進行測試
@Test
public void test04() throws IOException{
SqlSessionFactory sqlSessionFactory = getSqlSessionFactory();
//1、獲取到的SqlSession不會自動提交數據
SqlSession openSession = sqlSessionFactory.openSession();
try{
EmployeeMapper mapper = openSession.getMapper(EmployeeMapper.class);
Map<String, Employee> map = mapper.getEmpByLastNameLikeReturnMap("%e%");
System.out.println(map);
System.out.println("第一條記錄為："+map.get("jerry6@atguigu.com"));
System.out.println("第一條記錄為："+map.get("jerry6@atguigu.com").getEmail());
}finally{
openSession.close();
}
}