MyBatis一对一关系的查询
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2022-04-21 23:51:16
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1、有用户和代表团两个实体一个用户对应一个代表团
用户实体
package com.qf.meeting.pojo;
import java.io.Serializable;
import org.apache.log4j.LogManager;
import org.apache.log4j.Logger;
public class User implements Serializable{
private final static Logger LOG = LogManager.getLogger(User.class);
private Integer userId;
private String userLoginName;
private String userTel;
private String userPwd;
private String photo;
private String userName;
private Delegation delegation;
public User() {
super();
}
public User(Integer userId, String userLoginName, String userTel, String userPwd, String photo, String userName,
Delegation delegation) {
super();
this.userId = userId;
this.userLoginName = userLoginName;
this.userTel = userTel;
this.userPwd = userPwd;
this.photo = photo;
this.userName = userName;
this.delegation = delegation;
}
public Integer getUserId() {
return userId;
}
public void setUserId(Integer userId) {
this.userId = userId;
}
public String getUserLoginName() {
return userLoginName;
}
public void setUserLoginName(String userLoginName) {
this.userLoginName = userLoginName;
}
public String getUserTel() {
return userTel;
}
public void setUserTel(String userTel) {
this.userTel = userTel;
}
public String getUserPwd() {
return userPwd;
}
public void setUserPwd(String userPwd) {
this.userPwd = userPwd;
}
public String getPhoto() {
return photo;
}
public void setPhoto(String photo) {
this.photo = photo;
}
public String getUserName() {
return userName;
}
public void setUserName(String userName) {
this.userName = userName;
}
public Delegation getDelegation() {
return delegation;
}
public void setDelegation(Delegation delegation) {
this.delegation = delegation;
}
@Override
public String toString() {
return "User [userId=" + userId + ", userLoginName=" + userLoginName + ", userTel=" + userTel + ", userPwd="
+ userPwd + ", photo=" + photo + ", userName=" + userName + ", delegation=" + delegation + "]";
}
}
代表团实体
package com.qf.meeting.pojo;
import java.io.Serializable;
import org.apache.log4j.LogManager;
import org.apache.log4j.Logger;
public class Delegation implements Serializable{
private final static Logger LOG = LogManager.getLogger(Delegation.class);
private Integer delegationId;
private String delegationName;
public Delegation() {
super();
}
public Delegation(Integer delegationId, String delegationName) {
super();
this.delegationId = delegationId;
this.delegationName = delegationName;
}
public Integer getDelegationId() {
return delegationId;
}
public void setDelegationId(Integer delegationId) {
this.delegationId = delegationId;
}
public String getDelegationName() {
return delegationName;
}
public void setDelegationName(String delegationName) {
this.delegationName = delegationName;
}
@Override
public String toString() {
return "Delegation [delegationId=" + delegationId + ", delegationName=" + delegationName + "]";
}
}
2、查询所有的用户
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.qf.meeting.mapper.UserMapper">
<resultMap type="com.qf.meeting.pojo.User" id="UserResultMap">
<id property="userId" column="userId"/>
<result property="userLoginName" column="userLoginName"/>
<result property="userTel" column="userTel"/>
<result property="userPwd" column="userPwd"/>
<result property="photo" column="photo"/>
<result property="userName" column="userName"/>
<association property="delegation" column="delegationId" javaType="com.qf.meeting.pojo.Delegation" autoMapping="true">
<id property="delegationId" column="delegationId"/>
</association>
</resultMap>
<select id="findAllUser" resultMap="UserResultMap">
select * from t_user u ,t_delegation d where u.delegationId = d.delegationId;
</select>
</mapper>
查询结果
[{"userId":1,"userLoginName":"**","userTel":"*********","userPwd":"123456","photo":"***.jpg","userName":"****","delegation":{"delegationId":1,"delegationName":"电力局代表团"}}, {"userId":2,"userLoginName":"**","userTel":"*********","userPwd":"123456","photo":"***.jpg","userName":"***","delegation":{"delegationId":1,"delegationName":"电力局代表团"}}]
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