mybatis返回List
Mybatis返回如List形式的
POJO 类
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public class Design {
private int design_id;
private String idCreator ;
private String picName;
private String picUrl;
private String showText;
private Timestamp releaseTime;
private Timestamp endTime ;
}
public class FormData {
private int data_id ;
private String design_id ;
private String user_id ;
private Timestamp createTime;
private int isDelete ;
private String field1;
private String field2;
private String field3;
private String field4;
private String field5;
}
Controller 类
public class JoinController extends BaseController{
@Resource(name=”joinService”)
private JoinManager joinManager;
@ResponseBody
@RequestMapping( value=”getList.do” , produces= “application/json;charset=UTF-8”)
public Object getList( @RequestParam (value=”rd_session”) String rd_session ){
String openId = null ;
try {
openId = joinManager.getOpenIdByRd(rd_session);
} catch (Exception e) {
e.printStackTrace();
}
System.out.println(openId);
List————————————————————————————————————————————————————————————
JoinManager 接口
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public interface JoinManager {
// 通过rd_session获取 openid
public String getOpenIdByRd(String rd_session) throws Exception;
// 获取参与的 表单的 design_id List
public List}
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JoinService 实现类
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@Service(“joinService”)
public class JoinService implements JoinManager {
@Resource(name = "daoSupport")
private DaoSupport dao;
/**
* 获取openid
*/
@Override
public String getOpenIdByRd( String rd_session) {
return dao.getOpenIdByRd( "com.jy.entity.system.Join.findOpenId" ,rd_session) ;
}
@Override
public List}
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JoinMapper.xml
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PS:
1. 返回map时select列中最好设置别名。(经验证，当不设置别名时，你需要这个来取数据map.get(“count(*)”))。
select
count(*) as amount ,dt.data_id as sid, dg.design_id as sid , dg.title as title , dg.showText as text, dg.picUrl as url
from
- 在mybatis中，无论你指定还是不指定返回类型，mybatis都会默认的先将查询回的值放入一个hashMap中（如果返回的值不止一条就是一个包含hashMap的list）。这其中的区别在于，如果你指定了返回类型，mybatis将会根据返回类型的实体类来从hashMap中获取值并set到这个实体类中。如果不指定就默认返回一个HashMap