Mybatis之关联关系映射

一、一对多关联关系

1、实体类

首先先用逆向生成工具生成t_hibernate_order、t_hibernate_order_item
这两张表对应的model与mapper

①Order

package com.xnx.ssm.model;

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

//t_hibernate_order
//相当于添加了set/get方法，同时添加tostring
//@NoArgsConstructor
//@AllArgsConstructor
@Data
public class Order {
    private Integer orderId;

    private String orderNo;

}
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②OrderItem

package com.xnx.ssm.model;

import lombok.Data;
import lombok.ToString;

@ToString
public class OrderItem {
    private Integer orderItemId;

    private Integer productId;

    private Integer quantity;

    private Integer oid;

    public OrderItem(Integer orderItemId, Integer productId, Integer quantity, Integer oid) {
        this.orderItemId = orderItemId;
        this.productId = productId;
        this.quantity = quantity;
        this.oid = oid;
    }

    public OrderItem() {
        super();
    }

    public Integer getOrderItemId() {
        return orderItemId;
    }

    public void setOrderItemId(Integer orderItemId) {
        this.orderItemId = orderItemId;
    }

    public Integer getProductId() {
        return productId;
    }

    public void setProductId(Integer productId) {
        this.productId = productId;
    }

    public Integer getQuantity() {
        return quantity;
    }

    public void setQuantity(Integer quantity) {
        this.quantity = quantity;
    }

    public Integer getOid() {
        return oid;
    }

    public void setOid(Integer oid) {
        this.oid = oid;
    }
}
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2、Biz层

①OrderBiz

package com.xnx.ssm.biz;

import com.xnx.ssm.model.Book;
import com.xnx.ssm.model.BookVo;
import com.xnx.ssm.model.Order;
import com.xnx.ssm.model.vo.OrderVo;
import com.xnx.ssm.util.PageBean;
import org.apache.ibatis.annotations.Param;

import java.util.List;
import java.util.Map;

public interface OrderBiz {
    int deleteByPrimaryKey(Integer orderId);

    int insert(Order record);

    int insertSelective(Order record);

    Order selectByPrimaryKey(Integer orderId);

    OrderVo queryOrderVoByOrderId(Integer orderId);

    int updateByPrimaryKeySelective(Order record);

    int updateByPrimaryKey(Order record);
}

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②OrderItemBiz

package com.xnx.ssm.biz;

import com.xnx.ssm.model.OrderItem;
import com.xnx.ssm.model.vo.OrderItemVo;
import org.apache.ibatis.annotations.Param;

public interface OrderItemBiz {
    int deleteByPrimaryKey(Integer orderItemId);

    int insert(OrderItem record);

    int insertSelective(OrderItem record);

    OrderItem selectByPrimaryKey(Integer orderItemId);

    OrderItemVo queryOrderItemVoByOrderItemId(Integer orderItemId);

    int updateByPrimaryKeySelective(OrderItem record);

    int updateByPrimaryKey(OrderItem record);
}
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3、Biz的实现层Impl

①OrderBizImpl

package com.xnx.ssm.biz.impl;

import com.xnx.ssm.biz.OrderBiz;
import com.xnx.ssm.mapper.OrderMapper;
import com.xnx.ssm.model.Order;
import com.xnx.ssm.model.vo.OrderVo;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

@Service
public class OrderBizImpl implements OrderBiz {
    @Autowired
    private OrderMapper orderMapper;
    @Override
    public int deleteByPrimaryKey(Integer orderId) {
        return 0;
    }

    @Override
    public int insert(Order record) {
        return 0;
    }

    @Override
    public int insertSelective(Order record) {
        return 0;
    }

    @Override
    public Order selectByPrimaryKey(Integer orderId) {
        return null;
    }

    @Override
    public OrderVo queryOrderVoByOrderId(Integer orderId) {
        return orderMapper.queryOrderVoByOrderId(orderId);
    }

    @Override
    public int updateByPrimaryKeySelective(Order record) {
        return 0;
    }

    @Override
    public int updateByPrimaryKey(Order record) {
        return 0;
    }
}

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②OrderItemBizImpl

package com.xnx.ssm.biz.impl;

import com.xnx.ssm.biz.OrderItemBiz;
import com.xnx.ssm.mapper.OrderItemMapper;
import com.xnx.ssm.model.OrderItem;
import com.xnx.ssm.model.vo.OrderItemVo;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

@Service
public class OrderItemBizImpl implements OrderItemBiz {
    @Autowired
    private OrderItemMapper orderItemMapper;
    @Override
    public int deleteByPrimaryKey(Integer orderItemId) {
        return 0;
    }

    @Override
    public int insert(OrderItem record) {
        return 0;
    }

    @Override
    public int insertSelective(OrderItem record) {
        return 0;
    }

    @Override
    public OrderItem selectByPrimaryKey(Integer orderItemId) {
        return null;
    }

    @Override
    public OrderItemVo queryOrderItemVoByOrderItemId(Integer orderItemId) {
        return orderItemMapper.queryOrderItemVoByOrderItemId(orderItemId);
    }

    @Override
    public int updateByPrimaryKeySelective(OrderItem record) {
        return 0;
    }

    @Override
    public int updateByPrimaryKey(OrderItem record) {
        return 0;
    }
}

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4、mapper层

①OrderMapper.java

package com.xnx.ssm.mapper;

import com.xnx.ssm.model.Order;
import com.xnx.ssm.model.vo.OrderVo;
import org.apache.ibatis.annotations.Param;

public interface OrderMapper {
    int deleteByPrimaryKey(Integer orderId);

    int insert(Order record);

    int insertSelective(Order record);

    Order selectByPrimaryKey(Integer orderId);

    OrderVo queryOrderVoByOrderId(@Param("orderId") Integer orderId);

    int updateByPrimaryKeySelective(Order record);

    int updateByPrimaryKey(Order record);
}
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②OrderMapper.xml


DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd" >
<mapper namespace="com.xnx.ssm.mapper.OrderMapper" >
  <resultMap id="BaseResultMap" type="com.xnx.ssm.model.Order" >
    <constructor >
      <idArg column="order_id" jdbcType="INTEGER" javaType="java.lang.Integer" />
      <arg column="order_no" jdbcType="VARCHAR" javaType="java.lang.String" />
    constructor>
  resultMap>

  <resultMap id="OrderVoMap" type="com.xnx.ssm.model.vo.OrderVo" >
    <result column="order_id" property="orderId">result>
    <result column="order_no" property="orderNo">result>
    <collection property="orderItems" ofType="com.xnx.ssm.model.OrderItem">
      <result column="order_item_id" property="orderItemId">result>
      <result column="product_id" property="productId">result>
      <result column="quantity" property="quantity">result>
      <result column="oid" property="oid">result>
    collection>
  resultMap>

  <sql id="Base_Column_List" >
    order_id, order_no
  sql>

  <select id="queryOrderVoByOrderId" resultMap="OrderVoMap" parameterType="java.lang.Integer" >
    select * from t_hibernate_order o,t_hibernate_order_item oi where
    o.order_id=oi.oid and o.order_id=#{orderId}
  select>

  <select id="selectByPrimaryKey" resultMap="BaseResultMap" parameterType="java.lang.Integer" >
    select 
    <include refid="Base_Column_List" />
    from t_hibernate_order
    where order_id = #{orderId,jdbcType=INTEGER}
  select>
  <delete id="deleteByPrimaryKey" parameterType="java.lang.Integer" >
    delete from t_hibernate_order
    where order_id = #{orderId,jdbcType=INTEGER}
  delete>
  <insert id="insert" parameterType="com.xnx.ssm.model.Order" >
    insert into t_hibernate_order (order_id, order_no)
    values (#{orderId,jdbcType=INTEGER}, #{orderNo,jdbcType=VARCHAR})
  insert>
  <insert id="insertSelective" parameterType="com.xnx.ssm.model.Order" >
    insert into t_hibernate_order
    <trim prefix="(" suffix=")" suffixOverrides="," >
      <if test="orderId != null" >
        order_id,
      if>
      <if test="orderNo != null" >
        order_no,
      if>
    trim>
    <trim prefix="values (" suffix=")" suffixOverrides="," >
      <if test="orderId != null" >
        #{orderId,jdbcType=INTEGER},
      if>
      <if test="orderNo != null" >
        #{orderNo,jdbcType=VARCHAR},
      if>
    trim>
  insert>
  <update id="updateByPrimaryKeySelective" parameterType="com.xnx.ssm.model.Order" >
    update t_hibernate_order
    <set >
      <if test="orderNo != null" >
        order_no = #{orderNo,jdbcType=VARCHAR},
      if>
    set>
    where order_id = #{orderId,jdbcType=INTEGER}
  update>
  <update id="updateByPrimaryKey" parameterType="com.xnx.ssm.model.Order" >
    update t_hibernate_order
    set order_no = #{orderNo,jdbcType=VARCHAR}
    where order_id = #{orderId,jdbcType=INTEGER}
  update>
mapper>
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③OrderItemMapper.java

package com.xnx.ssm.mapper;

import com.xnx.ssm.model.OrderItem;
import com.xnx.ssm.model.vo.OrderItemVo;
import org.apache.ibatis.annotations.Param;

public interface OrderItemMapper {
    int deleteByPrimaryKey(Integer orderItemId);

    int insert(OrderItem record);

    int insertSelective(OrderItem record);

    OrderItem selectByPrimaryKey(Integer orderItemId);

    OrderItemVo queryOrderItemVoByOrderItemId(@Param("orderItemId") Integer orderItemId);

    int updateByPrimaryKeySelective(OrderItem record);

    int updateByPrimaryKey(OrderItem record);
}
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④OrderItemMapper.xml


DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd" >
<mapper namespace="com.xnx.ssm.mapper.OrderItemMapper" >
  <resultMap id="BaseResultMap" type="com.xnx.ssm.model.OrderItem" >
    <constructor >
      <idArg column="order_item_id" jdbcType="INTEGER" javaType="java.lang.Integer" />
      <arg column="product_id" jdbcType="INTEGER" javaType="java.lang.Integer" />
      <arg column="quantity" jdbcType="INTEGER" javaType="java.lang.Integer" />
      <arg column="oid" jdbcType="INTEGER" javaType="java.lang.Integer" />
    constructor>
  resultMap>

  <resultMap id="OrderItemVoMap" type="com.xnx.ssm.model.vo.OrderItemVo" >
    <result column="order_item_id" property="orderItemId">result>
    <result column="product_id" property="productId">result>
    <result column="quantity" property="quantity">result>
    <result column="oid" property="oid">result>
    <association property="order" javaType="com.xnx.ssm.model.Order">
      <result column="order_id" property="orderId">result>
      <result column="order_no" property="orderNo">result>
    association>
  resultMap>

  <sql id="Base_Column_List" >
    order_item_id, product_id,quantity,oid
  sql>

  <select id="queryOrderItemVoByOrderItemId" resultMap="OrderItemVoMap" parameterType="java.lang.Integer" >
    select * from t_hibernate_order o,t_hibernate_order_item oi where
o.order_id=oi.oid and oi.order_item_id=#{orderItemId}
  select>

  <select id="selectByPrimaryKey" resultMap="BaseResultMap" parameterType="java.lang.Integer" >
    select 
    <include refid="Base_Column_List" />
    from t_hibernate_order_item
    where order_item_id = #{orderItemId,jdbcType=INTEGER}
  select>
  <delete id="deleteByPrimaryKey" parameterType="java.lang.Integer" >
    delete from t_hibernate_order_item
    where order_item_id = #{orderItemId,jdbcType=INTEGER}
  delete>
  <insert id="insert" parameterType="com.xnx.ssm.model.OrderItem" >
    insert into t_hibernate_order_item (order_item_id, product_id, quantity, 
      oid)
    values (#{orderItemId,jdbcType=INTEGER}, #{productId,jdbcType=INTEGER}, #{quantity,jdbcType=INTEGER}, 
      #{oid,jdbcType=INTEGER})
  insert>
  <insert id="insertSelective" parameterType="com.xnx.ssm.model.OrderItem" >
    insert into t_hibernate_order_item
    <trim prefix="(" suffix=")" suffixOverrides="," >
      <if test="orderItemId != null" >
        order_item_id,
      if>
      <if test="productId != null" >
        product_id,
      if>
      <if test="quantity != null" >
        quantity,
      if>
      <if test="oid != null" >
        oid,
      if>
    trim>
    <trim prefix="values (" suffix=")" suffixOverrides="," >
      <if test="orderItemId != null" >
        #{orderItemId,jdbcType=INTEGER},
      if>
      <if test="productId != null" >
        #{productId,jdbcType=INTEGER},
      if>
      <if test="quantity != null" >
        #{quantity,jdbcType=INTEGER},
      if>
      <if test="oid != null" >
        #{oid,jdbcType=INTEGER},
      if>
    trim>
  insert>
  <update id="updateByPrimaryKeySelective" parameterType="com.xnx.ssm.model.OrderItem" >
    update t_hibernate_order_item
    <set >
      <if test="productId != null" >
        product_id = #{productId,jdbcType=INTEGER},
      if>
      <if test="quantity != null" >
        quantity = #{quantity,jdbcType=INTEGER},
      if>
      <if test="oid != null" >
        oid = #{oid,jdbcType=INTEGER},
      if>
    set>
    where order_item_id = #{orderItemId,jdbcType=INTEGER}
  update>
  <update id="updateByPrimaryKey" parameterType="com.xnx.ssm.model.OrderItem" >
    update t_hibernate_order_item
    set product_id = #{productId,jdbcType=INTEGER},
      quantity = #{quantity,jdbcType=INTEGER},
      oid = #{oid,jdbcType=INTEGER}
    where order_item_id = #{orderItemId,jdbcType=INTEGER}
  update>
mapper>
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5、测试类

①OrderBizImplTest

package com.xnx.ssm.biz.impl;

import com.xnx.ssm.biz.OrderBiz;
import com.xnx.ssm.model.Order;
import com.xnx.ssm.model.vo.OrderVo;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;

import static org.junit.Assert.*;

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations={"classpath:applicationContext-mybatis.xml"})
public class OrderBizImplTest {
    @Autowired
    private OrderBiz orderBiz;

    @Test
    public void queryOrderVoByOrderId() {
        OrderVo orderVo = orderBiz.queryOrderVoByOrderId(9);
        System.out.println(orderVo);
        orderVo.getOrderItems().forEach(System.out::println);
    }
}

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无@Data注解运行效果：
在这里插入图片描述
有@Data注解运行效果：

②OrderItemBizImplTest

jpa 关联映射jpa 关联映射jpa 关联映射

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package com.xnx.ssm.biz.impl;

import com.xnx.ssm.biz.OrderItemBiz;
import com.xnx.ssm.model.vo.OrderItemVo;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;

import static org.junit.Assert.*;

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations={"classpath:applicationContext-mybatis.xml"})
public class OrderItemBizImplTest {
    @Autowired
    private OrderItemBiz orderItemBiz;
    @Test
    public void queryOrderItemVoByOrderItemId() {
        OrderItemVo orderItemVo = orderItemBiz.queryOrderItemVoByOrderItemId(43);
        System.out.println(orderItemVo);
        System.out.println(orderItemVo.getOrder());
    }
}

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运行效果：
在这里插入图片描述

二、多对多关联关系

1、实体类

①Hbook

package com.xnx.ssm.model;

import lombok.ToString;

@ToString
public class Hbook {
    private Integer bookId;

    private String bookName;

    private Float price;

    public Hbook(Integer bookId, String bookName, Float price) {
        this.bookId = bookId;
        this.bookName = bookName;
        this.price = price;
    }

    public Hbook() {
        super();
    }

    public Integer getBookId() {
        return bookId;
    }

    public void setBookId(Integer bookId) {
        this.bookId = bookId;
    }

    public String getBookName() {
        return bookName;
    }

    public void setBookName(String bookName) {
        this.bookName = bookName;
    }

    public Float getPrice() {
        return price;
    }

    public void setPrice(Float price) {
        this.price = price;
    }
}
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②HbookCategory

package com.xnx.ssm.model;

public class HbookCategory {
    private Integer bcid;

    private Integer bid;

    private Integer cid;

    public HbookCategory(Integer bcid, Integer bid, Integer cid) {
        this.bcid = bcid;
        this.bid = bid;
        this.cid = cid;
    }

    public HbookCategory() {
        super();
    }

    public Integer getBcid() {
        return bcid;
    }

    public void setBcid(Integer bcid) {
        this.bcid = bcid;
    }

    public Integer getBid() {
        return bid;
    }

    public void setBid(Integer bid) {
        this.bid = bid;
    }

    public Integer getCid() {
        return cid;
    }

    public void setCid(Integer cid) {
        this.cid = cid;
    }
}
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2、biz层

①HbookCategoryBiz

package com.xnx.ssm.biz;

import com.xnx.ssm.model.HbookCategory;
import com.xnx.ssm.model.vo.CategoryVo;
import com.xnx.ssm.model.vo.HbookVo;
import org.apache.ibatis.annotations.Param;

public interface HbookCategoryBiz {
    int deleteByPrimaryKey(Integer bcid);

    int insert(HbookCategory record);

    int insertSelective(HbookCategory record);

    HbookCategory selectByPrimaryKey(Integer bcid);

    int updateByPrimaryKeySelective(HbookCategory record);

    int updateByPrimaryKey(HbookCategory record);

    HbookVo queryByBookId(Integer bookId);

    CategoryVo queryByCid(Integer cid);

}
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3、biz的实现层impl

①HbookCategoryBizImpl

package com.xnx.ssm.biz.impl;

import com.xnx.ssm.biz.HbookCategoryBiz;
import com.xnx.ssm.mapper.HbookCategoryMapper;
import com.xnx.ssm.model.HbookCategory;
import com.xnx.ssm.model.vo.CategoryVo;
import com.xnx.ssm.model.vo.HbookVo;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

@Service
public class HbookCategoryBizImpl implements HbookCategoryBiz {
    @Autowired
    private HbookCategoryMapper hbookCategoryMapper;
    @Override
    public int deleteByPrimaryKey(Integer bcid) {
        return 0;
    }

    @Override
    public int insert(HbookCategory record) {
        return 0;
    }

    @Override
    public int insertSelective(HbookCategory record) {
        return 0;
    }

    @Override
    public HbookCategory selectByPrimaryKey(Integer bcid) {
        return null;
    }

    @Override
    public int updateByPrimaryKeySelective(HbookCategory record) {
        return 0;
    }

    @Override
    public int updateByPrimaryKey(HbookCategory record) {
        return 0;
    }

    @Override
    public HbookVo queryByBookId(Integer bookId) {
        return hbookCategoryMapper.queryByBookId(bookId);
    }

    @Override
    public CategoryVo queryByCid(Integer cid) {
        return hbookCategoryMapper.queryByCid(cid);
    }
}

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4、mapper

①HbookCategoryMapper.java

package com.xnx.ssm.mapper;

import com.xnx.ssm.model.HbookCategory;
import com.xnx.ssm.model.vo.CategoryVo;
import com.xnx.ssm.model.vo.HbookVo;
import org.apache.ibatis.annotations.Param;

public interface HbookCategoryMapper {
    int deleteByPrimaryKey(Integer bcid);

    int insert(HbookCategory record);

    int insertSelective(HbookCategory record);

    HbookCategory selectByPrimaryKey(Integer bcid);

    int updateByPrimaryKeySelective(HbookCategory record);

    int updateByPrimaryKey(HbookCategory record);

    HbookVo queryByBookId(@Param("bookId") Integer bookId);

    CategoryVo queryByCid(@Param("cid") Integer cid);

}
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Spring+Hibernate 多对多关联映射---教师与学生表的级联增删改查

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②HbookCategoryMapper.xml


DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd" >
<mapper namespace="com.xnx.ssm.mapper.HbookCategoryMapper" >
  <resultMap id="BaseResultMap" type="com.xnx.ssm.model.HbookCategory" >
    <constructor >
      <idArg column="bcid" jdbcType="INTEGER" javaType="java.lang.Integer" />
      <arg column="bid" jdbcType="INTEGER" javaType="java.lang.Integer" />
      <arg column="cid" jdbcType="INTEGER" javaType="java.lang.Integer" />
    constructor>
  resultMap>
  <resultMap id="HbookVoMap" type="com.xnx.ssm.model.vo.HbookVo">
    <result property="bookId" column="book_id">result>
    <result property="bookName" column="book_name">result>
    <collection property="categories" ofType="com.xnx.ssm.model.Category">
      <result property="categoryId" column="category_id">result>
      <result property="categoryName" column="category_name">result>
    collection>
  resultMap>

  <resultMap id="CategoryVoMap" type="com.xnx.ssm.model.vo.CategoryVo">
    <result property="categoryId" column="category_id">result>
    <result property="categoryName" column="category_name">result>
    <collection property="hbooks" ofType="com.xnx.ssm.model.Hbook">
      <result property="bookId" column="book_id">result>
      <result property="bookName" column="book_name">result>
    collection>
  resultMap>
  <sql id="Base_Column_List" >
    bcid, bid, cid
  sql>


  <select id="queryByBookId" resultMap="HbookVoMap" parameterType="java.lang.Integer">
select * from t_hibernate_book b,t_hibernate_book_category bc,t_hibernate_category c
     where b.book_id = bc.bid and bc.cid = c.category_id and b.book_id = #{bookId}
 select>
  <select id="queryByCid" resultMap="CategoryVoMap" parameterType="java.lang.Integer">
select * from t_hibernate_book b,t_hibernate_book_category bc,t_hibernate_category c
     where b.book_id = bc.bid and bc.cid = c.category_id and c.category_id=#{cid}
   select>



  <select id="selectByPrimaryKey" resultMap="BaseResultMap" parameterType="java.lang.Integer" >
    select 
    <include refid="Base_Column_List" />
    from t_hibernate_book_category
    where bcid = #{bcid,jdbcType=INTEGER}
  select>
  <delete id="deleteByPrimaryKey" parameterType="java.lang.Integer" >
    delete from t_hibernate_book_category
    where bcid = #{bcid,jdbcType=INTEGER}
  delete>
  <insert id="insert" parameterType="com.xnx.ssm.model.HbookCategory" >
    insert into t_hibernate_book_category (bcid, bid, cid
      )
    values (#{bcid,jdbcType=INTEGER}, #{bid,jdbcType=INTEGER}, #{cid,jdbcType=INTEGER}
      )
  insert>
  <insert id="insertSelective" parameterType="com.xnx.ssm.model.HbookCategory" >
    insert into t_hibernate_book_category
    <trim prefix="(" suffix=")" suffixOverrides="," >
      <if test="bcid != null" >
        bcid,
      if>
      <if test="bid != null" >
        bid,
      if>
      <if test="cid != null" >
        cid,
      if>
    trim>
    <trim prefix="values (" suffix=")" suffixOverrides="," >
      <if test="bcid != null" >
        #{bcid,jdbcType=INTEGER},
      if>
      <if test="bid != null" >
        #{bid,jdbcType=INTEGER},
      if>
      <if test="cid != null" >
        #{cid,jdbcType=INTEGER},
      if>
    trim>
  insert>
  <update id="updateByPrimaryKeySelective" parameterType="com.xnx.ssm.model.HbookCategory" >
    update t_hibernate_book_category
    <set >
      <if test="bid != null" >
        bid = #{bid,jdbcType=INTEGER},
      if>
      <if test="cid != null" >
        cid = #{cid,jdbcType=INTEGER},
      if>
    set>
    where bcid = #{bcid,jdbcType=INTEGER}
  update>
  <update id="updateByPrimaryKey" parameterType="com.xnx.ssm.model.HbookCategory" >
    update t_hibernate_book_category
    set bid = #{bid,jdbcType=INTEGER},
      cid = #{cid,jdbcType=INTEGER}
    where bcid = #{bcid,jdbcType=INTEGER}
  update>
mapper>
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③HbookMapper.java

package com.xnx.ssm.mapper;

import com.xnx.ssm.model.Hbook;

public interface HbookMapper {
    int deleteByPrimaryKey(Integer bookId);

    int insert(Hbook record);

    int insertSelective(Hbook record);

    Hbook selectByPrimaryKey(Integer bookId);

    int updateByPrimaryKeySelective(Hbook record);

    int updateByPrimaryKey(Hbook record);
}
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④HbookMapper.xml


DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd" >
<mapper namespace="com.xnx.ssm.mapper.HbookMapper" >
  <resultMap id="BaseResultMap" type="com.xnx.ssm.model.Hbook" >
    <constructor >
      <idArg column="book_id" jdbcType="INTEGER" javaType="java.lang.Integer" />
      <arg column="book_name" jdbcType="VARCHAR" javaType="java.lang.String" />
      <arg column="price" jdbcType="REAL" javaType="java.lang.Float" />
    constructor>
  resultMap>
  <sql id="Base_Column_List" >
    book_id, book_name, price
  sql>



  <select id="selectByPrimaryKey" resultMap="BaseResultMap" parameterType="java.lang.Integer" >
    select 
    <include refid="Base_Column_List" />
    from t_hibernate_book
    where book_id = #{bookId,jdbcType=INTEGER}
  select>
  <delete id="deleteByPrimaryKey" parameterType="java.lang.Integer" >
    delete from t_hibernate_book
    where book_id = #{bookId,jdbcType=INTEGER}
  delete>
  <insert id="insert" parameterType="com.xnx.ssm.model.Hbook" >
    insert into t_hibernate_book (book_id, book_name, price
      )
    values (#{bookId,jdbcType=INTEGER}, #{bookName,jdbcType=VARCHAR}, #{price,jdbcType=REAL}
      )
  insert>
  <insert id="insertSelective" parameterType="com.xnx.ssm.model.Hbook" >
    insert into t_hibernate_book
    <trim prefix="(" suffix=")" suffixOverrides="," >
      <if test="bookId != null" >
        book_id,
      if>
      <if test="bookName != null" >
        book_name,
      if>
      <if test="price != null" >
        price,
      if>
    trim>
    <trim prefix="values (" suffix=")" suffixOverrides="," >
      <if test="bookId != null" >
        #{bookId,jdbcType=INTEGER},
      if>
      <if test="bookName != null" >
        #{bookName,jdbcType=VARCHAR},
      if>
      <if test="price != null" >
        #{price,jdbcType=REAL},
      if>
    trim>
  insert>
  <update id="updateByPrimaryKeySelective" parameterType="com.xnx.ssm.model.Hbook" >
    update t_hibernate_book
    <set >
      <if test="bookName != null" >
        book_name = #{bookName,jdbcType=VARCHAR},
      if>
      <if test="price != null" >
        price = #{price,jdbcType=REAL},
      if>
    set>
    where book_id = #{bookId,jdbcType=INTEGER}
  update>
  <update id="updateByPrimaryKey" parameterType="com.xnx.ssm.model.Hbook" >
    update t_hibernate_book
    set book_name = #{bookName,jdbcType=VARCHAR},
      price = #{price,jdbcType=REAL}
    where book_id = #{bookId,jdbcType=INTEGER}
  update>
mapper>
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4、vo层

①CategoryVo

package com.xnx.ssm.model.vo;

import com.xnx.ssm.model.Category;
import com.xnx.ssm.model.Hbook;

import java.util.List;

public class CategoryVo extends Category {
    public List<Hbook> getHbooks() {
        return hbooks;
    }

    public void setHbooks(List<Hbook> hbooks) {
        this.hbooks = hbooks;
    }

    private List<Hbook> hbooks;

}

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②HbookVo

package com.xnx.ssm.model.vo;

import com.xnx.ssm.model.Category;
import com.xnx.ssm.model.Hbook;

import java.util.List;

public class HbookVo extends Hbook {
    public List<Category> getCategories() {
        return categories;
    }

    public void setCategories(List<Category> categories) {
        this.categories = categories;
    }

    private List<Category> categories;

}

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5、测试类

①HbookCategoryBizImplTest

package com.xnx.ssm.biz.impl;

import com.xnx.ssm.biz.HbookCategoryBiz;
import com.xnx.ssm.model.vo.CategoryVo;
import com.xnx.ssm.model.vo.HbookVo;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;

import static org.junit.Assert.*;

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations={"classpath:applicationContext-mybatis.xml"})
public class HbookCategoryBizImplTest {
    @Autowired
    private HbookCategoryBiz hbookCategoryBiz;

    @Test
    public void queryByBookId() {
        HbookVo hbookVo = hbookCategoryBiz.queryByBookId(8);
        System.out.println(hbookVo);
        hbookVo.getCategories().forEach(System.out::println);
    }

    @Test
    public void queryByCid() {
        CategoryVo categoryVo=hbookCategoryBiz.queryByCid(8);
        System.out.println(categoryVo);
        categoryVo.getHbooks().forEach(System.out::println);
    }
}

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queryByBookId运行效果：
在这里插入图片描述

queryByCid运行效果：
在这里插入图片描述

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原文地址：https://blog.csdn.net/weixin_67677668/article/details/126352804

Mybatis之关联关系映射

目录

一、一对多关联关系

1、实体类

①Order

②OrderItem

2、Biz层

①OrderBiz

②OrderItemBiz

3、Biz的实现层Impl

①OrderBizImpl

②OrderItemBizImpl

4、mapper层

①OrderMapper.java

②OrderMapper.xml

③OrderItemMapper.java

④OrderItemMapper.xml

5、测试类

①OrderBizImplTest

②OrderItemBizImplTest

二、多对多关联关系

1、实体类

①Hbook

②HbookCategory

2、biz层

①HbookCategoryBiz

3、biz的实现层impl

①HbookCategoryBizImpl

4、mapper

①HbookCategoryMapper.java

②HbookCategoryMapper.xml

③HbookMapper.java

④HbookMapper.xml

4、vo层

①CategoryVo

②HbookVo

5、测试类

①HbookCategoryBizImplTest