继上一篇IBatis初体验

上一篇介绍了基本配置和一个简单的插入(其它RUD操作也类似)

本篇主要是对于一对多和多对一的基本使用

还是Userinfo 与 Score  双向一对多关系

javaBean:

public class Userinfo {

private int id;

private String userName;

private String pwd;

private int age;
 
 private List<Score>socresList=new ArrayList<Score>();

public void setAge(int age) {
  this.age = age;
 }

public int getId() {
  return id;
 }

public void setId(int id) {
  this.id = id;
 }

public String getUserName() {
  return userName;
 }

public void setUserName(String userName) {
  this.userName = userName;
 }

public String getPwd() {
  return pwd;
 }

public void setPwd(String pwd) {
  this.pwd = pwd;
 }

public Integer getAge() {
  return age;
 }

public void setAge(Integer age) {
  this.age = age;
 }

public List<Score> getSocresList() {
  return socresList;
 }

public void setSocresList(List<Score> socresList) {
  this.socresList = socresList;
 }
 
}

public class Score {

private int id;
 
 private int chinese;
 
 private int english;
 
 private Userinfo userinfo;
   
 public Userinfo getUserinfo() {
  return userinfo;
 }

public void setUserinfo(Userinfo userinfo) {
  this.userinfo = userinfo;
 }

public int getChinese() {
  return chinese;
 }

public void setChinese(int chinese) {
  this.chinese = chinese;
 }

public int getEnglish() {
  return english;
 }

public void setEnglish(int english) {
  this.english = english;
 }

public int getId() {
  return id;
 }

public void setId(int id) {
  this.id = id;
 }

}

sqlmap.xml：

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE sqlMap PUBLIC "-//ibatis.apache.org//DTD SQL Map 2.0//EN" "http://ibatis.apache.org/dtd/sql-map-2.dtd" >
<sqlMap namespace="UserInfo" >

<typeAlias alias="user" type="com.entity.Userinfo"/>
<typeAlias alias="score" type="com.entity.Score"/>

<insert id="abatorgenerated_insert" parameterClass="com.entity.Userinfo" >
     <selectKey resultClass="int" type="post" keyProperty="id" >  
           select @@IDENTITY as value  
    </selectKey>
    insert into UserInfo (userName, pwd, age)
                values (#userName:VARCHAR#, #pwd:VARCHAR#, #age:INTEGER#)
  </insert>
 
    <resultMap id="UserinfoResult" class="user" >
    <result column="id" property="id"  />
    <result column="userName" property="userName" jdbcType="VARCHAR" />
    <result column="pwd" property="pwd"  />
    <result column="age" property="age" />
    <result property="socresList"  column="id" select="getScoreByUserId"/><!-- 一对多关系体现 -->
    </resultMap>
 
   <resultMap id="s" class="score"    >
   <result property="id" column="id"/>
   <result property="chinese" column="chinese"/>
   <result property="english" column="english"/>
   <result property="userinfo" column="userId" select="getUserById"/><!-- 多对一关系体现 -->

</resultMap>
  
   <select id="getScoreByUserId" parameterClass="int"  resultMap="s">
   select * from score where userId=#id#
   </select>
  
   <select id="getUserById" resultClass="user" parameterClass="int">
   select * from userinfo where id=#userId#
   </select>
  
   <select id="getScore" resultMap="s">
   select * from score
   </select>
  
   <select id="getUserInfo" resultMap="UserinfoResult">
   select * from userinfo
   </select>
 
</sqlMap>

Test类：

List list = mapClient.queryForList("getUserInfo");//查询用户列表
   if (list.size() > 0) {
    
    //取第一个用户
    Userinfo userinfo = (Userinfo) list.get(0);
    System.out.println("用户:" + userinfo.getUserName());
    
    //取该用户的所有语文成绩
    for (Score score : userinfo.getSocresList()) {

System.out.println("语文:" + score.getChinese());
    }
   } else
    System.out.println("没有查到任何用户！");
   
   //多对一体现
   List list2=mapClient.queryForList("getScore");
   if (list2.size()>0) {
    
    Score score=(Score)list2.get(0);
    System.out.println(score.getUserinfo().getUserName()+" 的语文成绩是:"+score.getChinese());
   }
   else{
    System.out.println("无记录！");
   }

完毕！