• mybatis关联关系映射

    目录

    一、一对多关联关系

    1、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

    2、 编写一对多一方面OrderMapper.xml配置文件

    3、创建vo类（包含关联表的信息）

    4、在biz、impl里都添加方法

    5、创建测试类

    6、测试

     7、编写一对多多方面OrderItemMapper.xml配置文件

    二、多对多关联关系

    1、理论：多对多的核心就是两个一对多

    2、逆向生成代码

     3、创建vo类（包含关联表的信息）

    4、配置公共xml文件

    5、测试类

    6、运行

    一、一对多关联关系

    1、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

    1.  <table schema="" tableName="t_hibernate_order" domainObjectName="Order"
    2.            enableCountByExample="false" enableDeleteByExample="false"
    3.            enableSelectByExample="false" enableUpdateByExample="false">
    4.     table>
    5.     <table schema="" tableName="t_hibernate_order_item" domainObjectName="OrderItem"
    6.            enableCountByExample="false" enableDeleteByExample="false"
    7.            enableSelectByExample="false" enableUpdateByExample="false">
    8.     table>

     逆向生成

    2、 编写一对多一方面OrderMapper.xml配置文件

    2. mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd" >
    3. <mapper namespace="com.zking.ssm.mapper.OrderMapper" >
    4.   <resultMap id="BaseResultMap" type="com.zking.ssm.model.Order" >
    5.     <constructor >
    6.       <arg column="order_id" jdbcType="VARCHAR" javaType="java.lang.String" />
    7.       <arg column="order_no" jdbcType="VARCHAR" javaType="java.lang.String" />
    8.     constructor>
    9.   resultMap>
    10.  
    11.   <resultMap id="OrdervVoMap" type="com.zking.ssm.model.vo.OrdervVo" >
    12.     <result column="order_id" property="orderId">result>
    13.     <result column="order_no" property="orderNo">result>
    14.     <collection property="orderItems" ofType="com.zking.ssm.model.OrderItem">
    15.       <result column="order_item_id" property="orderItemId">result>
    16.       <result column="product_id" property="productId">result>
    17.       <result column="quantity" property="quantity">result>
    18.       <result column="oid" property="oid">result>
    19.     collection>
    20.   resultMap>
    21.  
    22.   <select id="queryOrderVoByOrderId" resultMap="OrdervVoMap" parameterType="java.lang.Integer">
    23.    select * from t_hibernate_order o,t_hibernate_order_item oi
    24.     where o.order_id = oi.oid
    25.     and o.order_id = #{orderId}
    26. select>
    27.  
    28.   <insert id="insert" parameterType="com.zking.ssm.model.Order" >
    29.     insert into t_hibernate_order (order_id, order_no)
    30.     values (#{orderId,jdbcType=VARCHAR}, #{orderNo,jdbcType=VARCHAR})
    31.   insert>
    32.   <insert id="insertSelective" parameterType="com.zking.ssm.model.Order" >
    33.     insert into t_hibernate_order
    34.     <trim prefix="(" suffix=")" suffixOverrides="," >
    35.       <if test="orderId != null" >
    36.         order_id,
    37.       if>
    38.       <if test="orderNo != null" >
    39.         order_no,
    40.       if>
    41.     trim>
    42.     <trim prefix="values (" suffix=")" suffixOverrides="," >
    43.       <if test="orderId != null" >
    44.         #{orderId,jdbcType=VARCHAR},
    45.       if>
    46.       <if test="orderNo != null" >
    47.         #{orderNo,jdbcType=VARCHAR},
    48.       if>
    49.     trim>
    50.   insert>
    51. mapper>

    3、创建vo类（包含关联表的信息）

    1. package com.zking.ssm.model.vo;
    2.  
    3. import com.zking.ssm.model.Order;
    4. import com.zking.ssm.model.OrderItem;
    5.  
    6. import java.util.List;
    7.  
    8. /**
    9.  * @author 白未
    10.  * @site 3185579318
    11.  * @company xxx公司
    12.  * @create  2022-08-16 9:21
    13.  *
    14.  * vo类不仅仅包含当前表的信息还能包含相关联表的信息
    15.  *
    16.  * 当前订单会有一个或者多个订单项，多个订单项必须要集合进行接收
    17.  */
    18. public class OrdervVo extends Order {
    19.     //通过订单号查询本次订单的详细信息及对应的所有订单项信息
    20.     private List orderItems;
    21.  
    22.     public List getOrderItems() {
    23.         return orderItems;
    24.     }
    25.  
    26.     public void setOrderItems(List orderItems) {
    27.         this.orderItems = orderItems;
    28.     }
    29. }
    30.

    给实体类添加注解@Data（相当于添加了set/get方法，同时添加了tostring方法）

    1. package com.zking.ssm.model;
    2.  
    3. import lombok.AllArgsConstructor;
    4. import lombok.Data;
    5. import lombok.NoArgsConstructor;
    6.  
    7. //t_hibernate_order
    8. //相当于添加了set/get方法，同时添加了tostring方法
    9. //@NoArgsConstructor
    10. //@AllArgsConstructor
    11. @Data
    12. public class Order {
    13.     private String orderId;
    14.  
    15.     private String orderNo;
    16.  
    17. }

    4、在biz、impl里都添加方法

    1. package com.zking.ssm.biz;
    2.  
    3. import com.zking.ssm.model.Order;
    4. import com.zking.ssm.model.vo.OrdervVo;
    5. import org.apache.ibatis.annotations.Param;
    6.  
    7. public interface OrderBiz {
    8.     int insert(Order record);
    9.  
    10.     int insertSelective(Order record);
    11.  
    12.  
    13.     OrdervVo queryOrderVoByOrderId(Integer orderId);
    14. }

    在impl里添加@Service注解

    1. package com.zking.ssm.biz.impl;
    2.  
    3. import com.zking.ssm.biz.OrderBiz;
    4. import com.zking.ssm.mapper.OrderMapper;
    5. import com.zking.ssm.model.Order;
    6. import com.zking.ssm.model.vo.OrdervVo;
    7. import org.springframework.beans.factory.annotation.Autowired;
    8. import org.springframework.stereotype.Service;
    9.  
    10. /**
    11.  * @author 白未
    12.  * @site 3185579318
    13.  * @company xxx公司
    14.  * @create  2022-08-16 9:55
    15.  */
    16. @Service
    17. public class OrderBizImpl implements OrderBiz {
    18.     @Autowired
    19.     private OrderMapper orderMapper;
    20.     @Override
    21.     public int insert(Order record) {
    22.         return 0;
    23.     }
    24.  
    25.     @Override
    26.     public int insertSelective(Order record) {
    27.         return 0;
    28.     }
    29.  
    30.     @Override
    31.     public OrdervVo queryOrderVoByOrderId(Integer orderId) {
    32.         return orderMapper.queryOrderVoByOrderId(orderId);
    33.     }
    34. }

    5、创建测试类

    1. package com.zking.ssm.biz.impl;
    2.  
    3. import com.zking.ssm.biz.OrderBiz;
    4. import com.zking.ssm.model.vo.OrdervVo;
    5. import org.apache.logging.log4j.core.config.Order;
    6. import org.junit.Test;
    7. import org.junit.runner.RunWith;
    8. import org.springframework.beans.factory.annotation.Autowired;
    9. import org.springframework.test.context.ContextConfiguration;
    10. import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
    11.  
    12. import static org.junit.Assert.*;
    13.  
    14. /**
    15.  * @author 白未
    16.  * @site 3185579318
    17.  * @company xxx公司
    18.  * @create  2022-08-16 9:58
    19.  */
    20. @RunWith(SpringJUnit4ClassRunner.class)
    21. @ContextConfiguration(locations={"classpath:applicationContext-mybatis.xml"})
    22. public class OrderBizImplTest {
    23.     @Autowired
    24.     private OrderBiz orderBiz;
    25.  
    26.  
    27.     @Test
    28.     public void queryOrderVoByOrderId() {
    29.         OrdervVo order = orderBiz.queryOrderVoByOrderId(9);
    30.         System.out.println(order);
    31.         order.getOrderItems().forEach(System.out::println);
    32.     }
    33. }

    6、测试

     7、编写一对多多方面OrderItemMapper.xml配置文件

    2. mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd" >
    3. <mapper namespace="com.zking.ssm.mapper.OrderItemMapper" >
    4.   <resultMap id="BaseResultMap" type="com.zking.ssm.model.OrderItem" >
    5.     <constructor >
    6.       <arg column="order_item_id" jdbcType="VARCHAR" javaType="java.lang.String" />
    7.       <arg column="product_id" jdbcType="VARCHAR" javaType="java.lang.String" />
    8.       <arg column="quantity" jdbcType="VARCHAR" javaType="java.lang.String" />
    9.       <arg column="oid" jdbcType="VARCHAR" javaType="java.lang.String" />
    10.     constructor>
    11.   resultMap>
    12.  
    13.   <resultMap id="OrderItemVoMap" type="com.zking.ssm.model.vo.OrderItemVo" >
    14.     <result column="order_item_id" property="orderItemId">result>
    15.     <result column="product_id" property="productId">result>
    16.     <result column="quantity" property="quantity">result>
    17.     <result column="oid" property="oid">result>
    18.     <association property="order" javaType="com.zking.ssm.model.Order">
    19.       <result column="order_id" property="orderId">result>
    20.       <result column="order_no" property="orderNo">result>
    21.     association>
    22.   resultMap>
    23.  
    24.   <select id="queryOrderItemVoByOrderItemId" resultMap="OrderItemVoMap" parameterType="java.lang.Integer">
    25.    select * from t_hibernate_order o,t_hibernate_order_item oi
    26.     where o.order_id = oi.oid
    27.     and oi.order_item_id = #{orderItemId}
    28. select>
    29.  
    30.   <insert id="insert" parameterType="com.zking.ssm.model.OrderItem" >
    31.     insert into t_hibernate_order_item (order_item_id, product_id, quantity, 
    32.       oid)
    33.     values (#{orderItemId,jdbcType=VARCHAR}, #{productId,jdbcType=VARCHAR}, #{quantity,jdbcType=VARCHAR}, 
    34.       #{oid,jdbcType=VARCHAR})
    35.   insert>
    36.   <insert id="insertSelective" parameterType="com.zking.ssm.model.OrderItem" >
    37.     insert into t_hibernate_order_item
    38.     <trim prefix="(" suffix=")" suffixOverrides="," >
    39.       <if test="orderItemId != null" >
    40.         order_item_id,
    41.       if>
    42.       <if test="productId != null" >
    43.         product_id,
    44.       if>
    45.       <if test="quantity != null" >
    46.         quantity,
    47.       if>
    48.       <if test="oid != null" >
    49.         oid,
    50.       if>
    51.     trim>
    52.     <trim prefix="values (" suffix=")" suffixOverrides="," >
    53.       <if test="orderItemId != null" >
    54.         #{orderItemId,jdbcType=VARCHAR},
    55.       if>
    56.       <if test="productId != null" >
    57.         #{productId,jdbcType=VARCHAR},
    58.       if>
    59.       <if test="quantity != null" >
    60.         #{quantity,jdbcType=VARCHAR},
    61.       if>
    62.       <if test="oid != null" >
    63.         #{oid,jdbcType=VARCHAR},
    64.       if>
    65.     trim>
    66.   insert>
    67. mapper>

    以下步骤与一方法相似就不一一展示了

    二、多对多关联关系

    1、理论：多对多的核心就是两个一对多

    2、逆向生成代码

    2. generatorConfiguration PUBLIC "-//mybatis.org//DTD MyBatis Generator Configuration 1.0//EN"
    3.         "http://mybatis.org/dtd/mybatis-generator-config_1_0.dtd" >
    4. <generatorConfiguration>
    5.     
    6.     <properties resource="jdbc.properties"/>
    7.  
    8.     
    9.     <classPathEntry location="E:\\AnZhuangBao\\Maven\\mvn_repository\\mysql\\mysql-connector-java\\5.1.44\\mysql-connector-java-5.1.44.jar"/>
    10.  
    11.     
    12.     <context id="infoGuardian">
    13.         
    14.         <commentGenerator>
    15.             <property name="suppressAllComments" value="true"/>
    16.             <property name="suppressDate" value="true"/> 
    17.         commentGenerator>
    18.  
    19.         
    20.         <jdbcConnection driverClass="${jdbc.driver}"
    21.                         connectionURL="${jdbc.url}" userId="${jdbc.username}" password="${jdbc.password}"/>
    22.  
    23.         
    24.         <javaTypeResolver>
    25.             
    26.             <property name="forceBigDecimals" value="false"/>
    27.         javaTypeResolver>
    28.  
    29.         
    30.         
    31.         
    32.         <javaModelGenerator targetPackage="com.leaf.ssm.model"
    33.                             targetProject="src/main/java">
    34.             
    35.             <property name="enableSubPackages" value="false"/>
    36.             
    37.             <property name="constructorBased" value="true"/>
    38.             
    39.             <property name="trimStrings" value="false"/>
    40.             
    41.             <property name="immutable" value="false"/>
    42.         javaModelGenerator>
    43.  
    44.         
    45.         <sqlMapGenerator targetPackage="com.leaf.ssm.mapper"
    46.                          targetProject="src/main/java">
    47.             
    48.             <property name="enableSubPackages" value="false"/>
    49.         sqlMapGenerator>
    50.  
    51.         
    52.         
    53.         
    54.         
    55.         <javaClientGenerator targetPackage="com.leaf.ssm.mapper"
    56.                              targetProject="src/main/java" type="XMLMAPPER">
    57.             
    58.             <property name="enableSubPackages" value="false"/>
    59.         javaClientGenerator>
    60.  
    61.         
    62.         
    63.         
    64.         
    65.         
    66.         
    67.         
    68.         
    69.         
    70.         
    71.         
    72.         
    73.         
    74.  
    75.         <table schema="" tableName="t_hibernate_book" domainObjectName="Hbook"
    76.                enableCountByExample="false" enableDeleteByExample="false"
    77.                enableSelectByExample="false" enableUpdateByExample="false">
    78.         table>
    79.  
    80.         <table schema="" tableName="t_hibernate_category" domainObjectName="Category"
    81.                enableCountByExample="false" enableDeleteByExample="false"
    82.                enableSelectByExample="false" enableUpdateByExample="false">
    83.         table>
    84.  
    85.         <table schema="" tableName="t_hibernate_book_category" domainObjectName="HbookCategory"
    86.                enableCountByExample="false" enableDeleteByExample="false"
    87.                enableSelectByExample="false" enableUpdateByExample="false">
    88.         table>
    89.  
    90.     context>
    91. generatorConfiguration>

    生成成功

     3、创建vo类（包含关联表的信息）

    1. package com.zking.ssm.model.vo;
    2.  
    3. import com.zking.ssm.model.Category;
    4. import com.zking.ssm.model.Hbook;
    5. import lombok.Data;
    6. import lombok.ToString;
    7.  
    8. import java.util.List;
    9.  
    10. /**
    11.  * @author 白未
    12.  * @site 3185579318
    13.  * @company xx公司
    14.  * @create  2022-08-16 11:36
    15.  */
    16. @Data
    17. public class CategoryVo extends Category {
    18.     private List hbooks;
    19.  
    20.     public List getHbooks() {
    21.         return hbooks;
    22.     }
    23.  
    24.     public void setHbooks(List hbooks) {
    25.         this.hbooks = hbooks;
    26.     }
    27. }
    1. package com.zking.ssm.model.vo;
    2.  
    3. import com.zking.ssm.model.Category;
    4. import com.zking.ssm.model.Hbook;
    5. import lombok.Data;
    6.  
    7. import java.util.List;
    8.  
    9. /**
    10.  * @author 白未
    11.  * @site 3185579318
    12.  * @company xx公司
    13.  * @create  2022-08-16 11:36
    14.  */
    15. @Data
    16. public class HbookVo extends Hbook {
    17.     private List categories;
    18.  
    19.     public List getCategories() {
    20.         return categories;
    21.     }
    22.  
    23.     public void setCategories(List categories) {
    24.         this.categories = categories;
    25.     }
    26. }

    4、配置公共xml文件

    2. mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd" >
    3. <mapper namespace="com.zking.ssm.mapper.HbookCategoryMapper" >
    4.   <resultMap id="BaseResultMap" type="com.zking.ssm.model.HbookCategory" >
    5.     <constructor >
    6.       <idArg column="bcid" jdbcType="INTEGER" javaType="java.lang.Integer" />
    7.       <arg column="bid" jdbcType="INTEGER" javaType="java.lang.Integer" />
    8.       <arg column="cid" jdbcType="INTEGER" javaType="java.lang.Integer" />
    9.     constructor>
    10.   resultMap>
    11.   <sql id="Base_Column_List" >
    12.     bcid, bid, cid
    13.   sql>
    14.  
    15.   <resultMap id="HbookVoMap" type="com.zking.ssm.model.vo.HbookVo">
    16.     <result property="bookId" column="book_id">result>
    17.     <result property="bookName" column="book_name">result>
    18.     <collection property="categories" ofType="com.zking.ssm.model.Category">
    19.       <result property="categoryId" column="category_id">result>
    20.       <result property="categoryName" column="category_name">result>
    21.     collection>
    22.   resultMap>
    23.  
    24.   <resultMap id="CategoryVoMap" type="com.zking.ssm.model.vo.CategoryVo">
    25.     <result property="categoryId" column="category_id">result>
    26.     <result property="categoryName" column="category_name">result>
    27.     <collection property="hbooks" ofType="com.zking.ssm.model.Hbook">
    28.       <result property="bookId" column="book_id">result>
    29.       <result property="bookName" column="book_name">result>
    30.     collection>
    31.   resultMap>
    32.  
    33.   <select id="queryByBookId" resultMap="HbookVoMap" parameterType="java.lang.Integer">
    34. select * from t_hibernate_book b,t_hibernate_book_category bc,t_hibernate_category c
    35.      where b.book_id = bc.bid and bc.cid = c.category_id and b.book_id = #{bookId}
    36.  select>
    37.   <select id="queryByCid" resultMap="CategoryVoMap" parameterType="java.lang.Integer">
    38. select * from t_hibernate_book b,t_hibernate_book_category bc,t_hibernate_category c
    39.      where b.book_id = bc.bid and bc.cid = c.category_id and c.category_id=#{cid}
    40.    select>
    41.  
    42.   <select id="selectByPrimaryKey" resultMap="BaseResultMap" parameterType="java.lang.Integer" >
    43.     select 
    44.     <include refid="Base_Column_List" />
    45.     from t_hibernate_book_category
    46.     where bcid = #{bcid,jdbcType=INTEGER}
    47.   select>
    48.   <delete id="deleteByPrimaryKey" parameterType="java.lang.Integer" >
    49.     delete from t_hibernate_book_category
    50.     where bcid = #{bcid,jdbcType=INTEGER}
    51.   delete>
    52.   <insert id="insert" parameterType="com.leaf.ssm.model.HbookCategory" >
    53.     insert into t_hibernate_book_category (bcid, bid, cid
    54.       )
    55.     values (#{bcid,jdbcType=INTEGER}, #{bid,jdbcType=INTEGER}, #{cid,jdbcType=INTEGER}
    56.       )
    57.   insert>
    58.   <insert id="insertSelective" parameterType="com.zking.ssm.model.HbookCategory" >
    59.     insert into t_hibernate_book_category
    60.     <trim prefix="(" suffix=")" suffixOverrides="," >
    61.       <if test="bcid != null" >
    62.         bcid,
    63.       if>
    64.       <if test="bid != null" >
    65.         bid,
    66.       if>
    67.       <if test="cid != null" >
    68.         cid,
    69.       if>
    70.     trim>
    71.     <trim prefix="values (" suffix=")" suffixOverrides="," >
    72.       <if test="bcid != null" >
    73.         #{bcid,jdbcType=INTEGER},
    74.       if>
    75.       <if test="bid != null" >
    76.         #{bid,jdbcType=INTEGER},
    77.       if>
    78.       <if test="cid != null" >
    79.         #{cid,jdbcType=INTEGER},
    80.       if>
    81.     trim>
    82.   insert>
    83.   <update id="updateByPrimaryKeySelective" parameterType="com.zking.ssm.model.HbookCategory" >
    84.     update t_hibernate_book_category
    85.     <set >
    86.       <if test="bid != null" >
    87.         bid = #{bid,jdbcType=INTEGER},
    88.       if>
    89.       <if test="cid != null" >
    90.         cid = #{cid,jdbcType=INTEGER},
    91.       if>
    92.     set>
    93.     where bcid = #{bcid,jdbcType=INTEGER}
    94.   update>
    95.   <update id="updateByPrimaryKey" parameterType="com.zking.ssm.model.HbookCategory" >
    96.     update t_hibernate_book_category
    97.     set bid = #{bid,jdbcType=INTEGER},
    98.       cid = #{cid,jdbcType=INTEGER}
    99.     where bcid = #{bcid,jdbcType=INTEGER}
    100.   update>
    101. mapper>

    5、测试类

    1. package com.zking.ssm.biz.impl;
    2.  
    3. import com.zking.ssm.biz.HbookCategoryBiz;
    4. import com.zking.ssm.model.vo.CategoryVo;
    5. import com.zking.ssm.model.vo.HbookVo;
    6. import org.junit.Test;
    7. import org.junit.runner.RunWith;
    8. import org.springframework.beans.factory.annotation.Autowired;
    9. import org.springframework.test.context.ContextConfiguration;
    10. import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
    11.  
    12. import static org.junit.Assert.*;
    13.  
    14. /**
    15.  * @author zking
    16.  * @site 3185579318
    17.  * @company xx公司
    18.  * @create  2022-08-16 11:43
    19.  */
    20. @RunWith(SpringJUnit4ClassRunner.class)
    21. @ContextConfiguration(locations={"classpath:applicationContext-mybatis.xml"})
    22. public class HbookCategoryBizImplTest {
    23.  
    24.     @Autowired
    25.     private HbookCategoryBiz hbookCategoryBiz;
    26.  
    27.     @Test
    28.     public void queryByBookId() {
    29.         HbookVo hbookVo = hbookCategoryBiz.queryByBookId(8);
    30.         System.out.println(hbookVo);
    31.     }
    32.  
    33.     @Test
    34.     public void queryByCid() {
    35.         CategoryVo categoryVo = hbookCategoryBiz.queryByCid(8);
    36.         System.out.println(categoryVo);
    37.     }
    38. }

    6、运行

     

     

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  • 原文地址：https://blog.csdn.net/yzq102873/article/details/126358614