Java mybatis一对一和一对多嵌套查询

问题遇到的现象和发生背景

java: 需要class, interface或enum

问题相关代码，请勿粘贴截图

1.Bill.xml

<?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元素的namespace 属性的值为对应 mapper的全限定类名：路径+类的名称。通过该方法关联接口和XML文件-->
<mapper namespace="mapper.BillMapper">
    <!--一对一-->
    <resultMap id="mybill" type="bill" autoMapping="true">
        <id property="id" column="id"/>
        <result property="billCode" column="billCode"/>

        <association property="provider" javaType="provider" autoMapping="true"
                     column="pid"
                     select="ProviderMapper.findProviderById">
            <id property="id" column="pid"/>
            <result property="proname" column="proname"/>
        </association>
    </resultMap>

    <select id="findBillByIdWithProvider" resultMap="mybill">
        select * from smbms_bill where id = #{id}
    </select>

    <!--一对多-->
    <select id="findBillByPid" resultType="bill">
        select * from smbms_bill where pid = #{pid}
    </select>

    <resultMap id="myprovider" type="provider" autoMapping="true">
        <id property="id" column="id"/>

        <collection property="list" ofType="bill" autoMapping="true"
                    column="id"
                    select="BillMapper.findBillByPid">
            <id property="id" column="oid"/>
        </collection>
    </resultMap>

    <select id="findProviderByIdWithBill" resultMap="myprovider">
        select * from smbms_bill where provider.id = #{pid}
    </select>

</mapper>

2.BillMapper

package mapper;


import pojo.smbms_bill;
import pojo.smbms_provider;

import java.util.List;

public interface BillMapper {
    //一对一关系
    smbms_bill findBillByIdWithProvider(int id);

    //一对多关系
    smbms_provider findProviderByIdWithBill(int pid);
    List<smbms_bill> findBillByPid(int pid);

}

3.Provider.xml

<?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元素的namespace 属性的值为对应 mapper的全限定类名：路径+类的名称。通过该方法关联接口和XML文件-->

<mapper namespace="mapper.ProviderMapper">

      <select id="findProviderById" resultType="user">
          select * from smbms_provider where id = #{id}
      </select>

</mapper>

4.ProviderMapper

package mapper;

import pojo.smbms_provider;

public interface ProviderMapper {

    smbms_provider findProviderById(int id);
}

5.smbms_bill实体类

package pojo;

import java.util.Date;
//订单
public class smbms_bill {
    private int id;
    private String billCode;
    private String productName;
    private String productDesc;
    private String productUnit;
    private int productCount;
    private int totalPrice;
    private int isPayment;
    private int createdBy;
    private Date creationDate;
    private  int modifyBy;
    private Date modifyDate;

    private  int providerId; //外键

    private smbms_provider provider; //订单对应供应商

    public smbms_bill() {
    }

    public smbms_bill(int id, String billCode, String productName, String productDesc, String productUnit, int productCount, int totalPrice, int isPayment, int createdBy, Date creationDate, int modifyBy, Date modifyDate, int providerId, smbms_provider provider) {
        this.id = id;
        this.billCode = billCode;
        this.productName = productName;
        this.productDesc = productDesc;
        this.productUnit = productUnit;
        this.productCount = productCount;
        this.totalPrice = totalPrice;
        this.isPayment = isPayment;
        this.createdBy = createdBy;
        this.creationDate = creationDate;
        this.modifyBy = modifyBy;
        this.modifyDate = modifyDate;
        this.providerId = providerId;
        this.provider = provider;
    }

    public int getId() {
        return id;
    }

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

    public String getBillCode() {
        return billCode;
    }

    public void setBillCode(String billCode) {
        this.billCode = billCode;
    }

    public String getProductName() {
        return productName;
    }

    public void setProductName(String productName) {
        this.productName = productName;
    }

    public String getProductDesc() {
        return productDesc;
    }

    public void setProductDesc(String productDesc) {
        this.productDesc = productDesc;
    }

    public String getProductUnit() {
        return productUnit;
    }

    public void setProductUnit(String productUnit) {
        this.productUnit = productUnit;
    }

    public int getProductCount() {
        return productCount;
    }

    public void setProductCount(int productCount) {
        this.productCount = productCount;
    }

    public int getTotalPrice() {
        return totalPrice;
    }

    public void setTotalPrice(int totalPrice) {
        this.totalPrice = totalPrice;
    }

    public int getIsPayment() {
        return isPayment;
    }

    public void setIsPayment(int isPayment) {
        this.isPayment = isPayment;
    }

    public int getCreatedBy() {
        return createdBy;
    }

    public void setCreatedBy(int createdBy) {
        this.createdBy = createdBy;
    }

    public Date getCreationDate() {
        return creationDate;
    }

    public void setCreationDate(Date creationDate) {
        this.creationDate = creationDate;
    }

    public int getModifyBy() {
        return modifyBy;
    }

    public void setModifyBy(int modifyBy) {
        this.modifyBy = modifyBy;
    }

    public Date getModifyDate() {
        return modifyDate;
    }

    public void setModifyDate(Date modifyDate) {
        this.modifyDate = modifyDate;
    }

    public int getProviderId() {
        return providerId;
    }

    public void setProviderId(int providerId) {
        this.providerId = providerId;
    }

    public smbms_provider getProvider() {
        return provider;
    }

    public void setProvider(smbms_provider provider) {
        this.provider = provider;
    }

    @Override
    public String toString() {
        return "smbms_bill{" +
                "id=" + id +
                ", billCode='" + billCode + '\'' +
                ", productName='" + productName + '\'' +
                ", productDesc='" + productDesc + '\'' +
                ", productUnit='" + productUnit + '\'' +
                ", productCount=" + productCount +
                ", totalPrice=" + totalPrice +
                ", isPayment=" + isPayment +
                ", createdBy=" + createdBy +
                ", creationDate=" + creationDate +
                ", modifyBy=" + modifyBy +
                ", modifyDate=" + modifyDate +
                ", providerId=" + providerId +
                ", provider=" + provider +
                '}';
    }

6.smbms_provider实体类

package pojo;

import java.util.Date;
import java.util.List;
//供应商
public class smbms_provider {
    private int id;
    private String proCode;
    private String proName;
    private String proDesc;
    private String proContact;
    private String proPhone;
    private String proAddress;
    private String proFax;
    private int createdBy;
    private Date creationDate;
    private Date modifyDate;
    private  int modifyBy;
    //地址信息，一对多的关系，多就需要用List接收，该属性在数据库表中并没有
    private List<smbms_bill> billList;

    public smbms_provider() {
    }

    public smbms_provider(int id, String proCode, String proName, String proDesc, String proContact, String proPhone, String proAddress, String proFax, int createdBy, Date creationDate, Date modifyDate, int modifyBy, List<smbms_bill> billList) {
        this.id = id;
        this.proCode = proCode;
        this.proName = proName;
        this.proDesc = proDesc;
        this.proContact = proContact;
        this.proPhone = proPhone;
        this.proAddress = proAddress;
        this.proFax = proFax;
        this.createdBy = createdBy;
        this.creationDate = creationDate;
        this.modifyDate = modifyDate;
        this.modifyBy = modifyBy;
        this.billList = billList;
    }

    public int getId() {
        return id;
    }

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

    public String getProCode() {
        return proCode;
    }

    public void setProCode(String proCode) {
        this.proCode = proCode;
    }

    public String getProName() {
        return proName;
    }

    public void setProName(String proName) {
        this.proName = proName;
    }

    public String getProDesc() {
        return proDesc;
    }

    public void setProDesc(String proDesc) {
        this.proDesc = proDesc;
    }

    public String getProContact() {
        return proContact;
    }

    public void setProContact(String proContact) {
        this.proContact = proContact;
    }

    public String getProPhone() {
        return proPhone;
    }

    public void setProPhone(String proPhone) {
        this.proPhone = proPhone;
    }

    public String getProAddress() {
        return proAddress;
    }

    public void setProAddress(String proAddress) {
        this.proAddress = proAddress;
    }

    public String getProFax() {
        return proFax;
    }

    public void setProFax(String proFax) {
        this.proFax = proFax;
    }

    public int getCreatedBy() {
        return createdBy;
    }

    public void setCreatedBy(int createdBy) {
        this.createdBy = createdBy;
    }

    public Date getCreationDate() {
        return creationDate;
    }

    public void setCreationDate(Date creationDate) {
        this.creationDate = creationDate;
    }

    public Date getModifyDate() {
        return modifyDate;
    }

    public void setModifyDate(Date modifyDate) {
        this.modifyDate = modifyDate;
    }

    public int getModifyBy() {
        return modifyBy;
    }

    public void setModifyBy(int modifyBy) {
        this.modifyBy = modifyBy;
    }

    public List<smbms_bill> getBillList() {
        return billList;
    }

    public void setBillList(List<smbms_bill> billList) {
        this.billList = billList;
    }

    @Override
    public String toString() {
        return "smbms_provider{" +
                "id=" + id +
                ", proCode='" + proCode + '\'' +
                ", proName='" + proName + '\'' +
                ", proDesc='" + proDesc + '\'' +
                ", proContact='" + proContact + '\'' +
                ", proPhone='" + proPhone + '\'' +
                ", proAddress='" + proAddress + '\'' +
                ", proFax='" + proFax + '\'' +
                ", createdBy=" + createdBy +
                ", creationDate=" + creationDate +
                ", modifyDate=" + modifyDate +
                ", modifyBy=" + modifyBy +
                ", billList=" + billList +
                '}';
    }
}

7.测试

 System.out.println("+++++++++(一对一)++++++++++++");
            //一对一和一对多的级联查询(一个供应商提供多个订单,一个订单对应一个供应商)
            //嵌套查询的方式
            BillMapper mapper = sqlSession.getMapper(BillMapper.class);
            smbms_bill bill = mapper.findBillByIdWithProvider(1);
            System.out.println(bill);

            System.out.println("+++++++++(一对多)++++++++++++");
            mapper = sqlSession.getMapper(BillMapper.class);
            smbms_provider provider = mapper.findProviderByIdWithBill(1);
            System.out.println(provider);

8.数据库建表

create table smbms_bill(
    id bigint(20),
    billCode varchar(20),
    productName varchar(20),
    productDesc varchar(50), 
    productUnit varchar(10),
    productCount decimal(20,2),
    totalPrice decimal(20,2),
    isPayment int(10),
    createdBy bigint(20),
    creationDate datetime,
    modifyBy bigint(20),
    modifyDate datetime,
    providerId bigint(20)   
);
 id bigint(20),
    proCode varchar(20),
    proName varchar(20),
    proDesc varchar(50), 
    proContact varchar(20),
    proPhone varchar(20),
    proAddress varchar(50),
    proFax varchar(20),
    createdBy bigint(20),
    creationDate datetime,
    modifyDate datetime, 
    modifyBy bigint(20)

运行结果及报错内容

我的解答思路和尝试过的方法

可能是代码不对应

我想要达到的结果

可以正常查询

这些类型如果没有设置别名的话，需要写类的全类名(带包名的)