mybatis 使用resultMap实现关联数据的查询（association 和collection ）

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="cn.bdqn.dao.UserMapper">
    
     
    
    
    
    
    <resultMap type="User" id="seachUserResult">
        <result property="id" column="id"/>
        <result property="userCode" column="userCode" />
        <result property="userName" column="userName" />
        <result property="roleId" column="roleId" />
　　　　//property=“属性名” javaType=“属性名的类型” ----（一对一）

        
        <association property="role" javaType="Role" resultMap="roleMap"/>
    resultMap>
    
    <resultMap type="Role" id="roleMap">
        <result property="id" column="id"/> 
        <result property="roleCode" column="roleCode"/> 
        <result property="roleName" column="roleName"/> 
    resultMap>
    
    <select id="getUserListByRoleId" parameterType="Role" resultMap="seachUserResult">
        select u.*,r.roleCode as roleCode,r.roleName as roleName from user u,role r where u.roleId = r.id and u.roleId = #{id}
    select>
    
    
    
    
    <resultMap type="User" id="userMap">
        <id property="id" column="userId"/>
　　　　//property是属性名  ofType是List《Address》的类对象

        <collection property="addressList" ofType="Address">
            <id property="id" column="a_id"/>
            <result property="postCode" column="postCode"/>
            <result property="addressContent" column="addressContent"/>
        collection>
    resultMap>
    
    <select id="getAddressListByUserId" parameterType="User" resultMap="userMap">
        select *,a.id as a_id from user u,address a where u.id=a.userId and u.id=#{id}
    select>
    
    
    <select id="count" resultType="int">
        select count(1) from user
    select>
    
    <insert id="add" parameterType="User">
        insert into user (userCode,userName,userPassword) 
            values (#{userCode},#{userName},#{userPassword})
    insert>
    
    <update id="update" parameterType="User">
        update user set userCode=#{userCode},userName=#{userName},
            userPassword=#{userPassword} where id=#{id}
    update>
    
    <delete id="delete" parameterType="User">
        delete from user where id=#{id}
    delete>
    
    <select id="getUserList" resultType="User">
        select * from user
    select>
mapper>

接口 UserMapper 

public interface UserMapper {
    
    public int count();
    
    public void add(User user);
    
    public void update(User user);
    
    public void delete(User user);
    
    public List getUserList();
    
    //根据roleId获取用户列表
    public List getUserListByRoleId(Role role);
    
    //获取指定用户的地址列表(user表-address表：1对多关系)
    public User getAddressListByUserId(User user);
    
}

接口 RoleMapper 

public interface RoleMapper {
    
    public void add(Role role);
    
    public void update(Role role);
    
    public void delete(Role role);
    
    public List getRoleList();
}

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="cn.bdqn.dao.RoleMapper">
    <select id="getRoleList" resultType="Role">
        select * from role
    select>
    
    <insert id="add" parameterType="Role">
        insert into role (roleCode,roleName) 
            values (#{roleCode},#{roleName})
    insert>
    
    <update id="update" parameterType="Role">
        update role set roleCode=#{roleCode},roleName=#{roleName}
            where id=#{id}
    update>
    
    <delete id="delete" parameterType="Role">
        delete from role where id=#{id}
    delete>

mapper>

User.java

public class User {
    private Integer id;
    private String userName;
    private String userCode;
    private String userPassword;
    private Integer roleId;
    //private String roleName;
    
    //collection
    private List
 addressList;
    
    //association
    private Role role;
    
    
    public Role getRole() {
        return role;
    }
    public void setRole(Role role) {
        this.role = role;
    }
    public List
 getAddressList() {
        return addressList;
    }
    public void setAddressList(List
 addressList) {
        this.addressList = addressList;
    }
    public Integer getRoleId() {
        return roleId;
    }
    public void setRoleId(Integer roleId) {
        this.roleId = roleId;
    }
    /**
    public String getRoleName() {
        return roleName;
    }
    public void setRoleName(String roleName) {
        this.roleName = roleName;
    }
    */
    public Integer getId() {
        return id;
    }
    public void setId(Integer id) {
        this.id = id;
    }
    public String getUserName() {
        return userName;
    }
    public void setUserName(String userName) {
        this.userName = userName;
    }
    public String getUserCode() {
        return userCode;
    }
    public void setUserCode(String userCode) {
        this.userCode = userCode;
    }
    public String getUserPassword() {
        return userPassword;
    }
    public void setUserPassword(String userPassword) {
        this.userPassword = userPassword;
    }
    
}

address.java

public class Address {
    private Integer id;
    private Integer postCode;
    private String addressContent;
    public Integer getId() {
        return id;
    }
    public void setId(Integer id) {
        this.id = id;
    }
    public Integer getPostCode() {
        return postCode;
    }
    public void setPostCode(Integer postCode) {
        this.postCode = postCode;
    }
    public String getAddressContent() {
        return addressContent;
    }
    public void setAddressContent(String addressContent) {
        this.addressContent = addressContent;
    }
    
}

 

转载于:https://www.cnblogs.com/xuerong/p/5000233.html