SSM--关联关系映射

目录

  • 一、一对多关联关系
    • 1.1 逆向生成代码配置文件
    • 1.2 编写配置文件:OrderMapper.xml
    • 1.3 建立Vo类
  • 二、多对对
    • 2.1 逆向生成代码
    • 2.2 创建Vo类

一、一对多关联关系

需求:通过订单号查询本次订单的详情信息以及对应的所有订单

1.1 逆向生成代码配置文件

generatorConfig.xml

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE generatorConfiguration PUBLIC "-//mybatis.org//DTD MyBatis Generator Configuration 1.0//EN"
        "http://mybatis.org/dtd/mybatis-generator-config_1_0.dtd" >
<generatorConfiguration>
    <!-- 引入配置文件 -->
    <properties resource="jdbc.properties"/>

    <!--指定数据库jdbc驱动jar包的位置-->
    <classPathEntry location="E:\\maven\\mavenjar\\mysql\\mysql-connector-java\\5.1.44\\mysql-connector-java-5.1.44.jar"/>

    <!-- 一个数据库一个context -->
    <context id="infoGuardian">
        <!-- 注释 -->
        <commentGenerator>
            <property name="suppressAllComments" value="true"/><!-- 是否取消注释 -->
            <property name="suppressDate" value="true"/> <!-- 是否生成注释代时间戳 -->
        </commentGenerator>

        <!-- jdbc连接 -->
        <jdbcConnection driverClass="${jdbc.driver}"
                        connectionURL="${jdbc.url}" userId="${jdbc.username}" password="${jdbc.password}"/>

        <!-- 类型转换 -->
        <javaTypeResolver>
            <!-- 是否使用bigDecimal, false可自动转化以下类型(Long, Integer, Short, etc.-->
            <property name="forceBigDecimals" value="false"/>
        </javaTypeResolver>

        <!-- 01 指定javaBean生成的位置 -->
        <!-- targetPackage:指定生成的model生成所在的包名 -->
        <!-- targetProject:指定在该项目下所在的路径  -->
        <javaModelGenerator targetPackage="com.xlb.ssm.model"
                            targetProject="src/main/java">
            <!-- 是否允许子包,即targetPackage.schemaName.tableName -->
            <property name="enableSubPackages" value="false"/>
            <!-- 是否对model添加构造函数 -->
            <property name="constructorBased" value="true"/>
            <!-- 是否针对string类型的字段在set的时候进行trim调用 -->
            <property name="trimStrings" value="false"/>
            <!-- 建立的Model对象是否 不可改变  即生成的Model对象不会有 setter方法,只有构造方法 -->
            <property name="immutable" value="false"/>
        </javaModelGenerator>

        <!-- 02 指定sql映射文件生成的位置 -->
        <sqlMapGenerator targetPackage="com.xlb.ssm.mapper"
                         targetProject="src/main/java">
            <!-- 是否允许子包,即targetPackage.schemaName.tableName -->
            <property name="enableSubPackages" value="false"/>
        </sqlMapGenerator>

        <!-- 03 生成XxxMapper接口 -->
        <!-- type="ANNOTATEDMAPPER",生成Java Model 和基于注解的Mapper对象 -->
        <!-- type="MIXEDMAPPER",生成基于注解的Java Model 和相应的Mapper对象 -->
        <!-- type="XMLMAPPER",生成SQLMap XML文件和独立的Mapper接口 -->
        <javaClientGenerator targetPackage="com.xlb.ssm.mapper"
                             targetProject="src/main/java" type="XMLMAPPER">
            <!-- 是否在当前路径下新加一层schema,false路径com.oop.eksp.user.model, true:com.oop.eksp.user.model.[schemaName] -->
            <property name="enableSubPackages" value="false"/>
        </javaClientGenerator>

        <!-- 配置表信息 -->
        <!-- schema即为数据库名 -->
        <!-- tableName为对应的数据库表 -->
        <!-- domainObjectName是要生成的实体类 -->
        <!-- enable*ByExample是否生成 example类 -->
        <!--<table schema="" tableName="t_book" domainObjectName="Book"-->
        <!--enableCountByExample="false" enableDeleteByExample="false"-->
        <!--enableSelectByExample="false" enableUpdateByExample="false">-->
        <!--&lt;!&ndash; 忽略列,不生成bean 字段 &ndash;&gt;-->
        <!--&lt;!&ndash; <ignoreColumn column="FRED" /> &ndash;&gt;-->
        <!--&lt;!&ndash; 指定列的java数据类型 &ndash;&gt;-->
        <!--&lt;!&ndash; <columnOverride column="LONG_VARCHAR_FIELD" jdbcType="VARCHAR" /> &ndash;&gt;-->
        <!--</table>-->

       <table schema="" tableName="t_hibernate_order" domainObjectName="Order"
               enableCountByExample="false" enableDeleteByExample="false"
               enableSelectByExample="false" enableUpdateByExample="false">
        </table>
 
        <table schema="" tableName="t_hibernate_order_item" domainObjectName="OrderItem"
               enableCountByExample="false" enableDeleteByExample="false"
               enableSelectByExample="false" enableUpdateByExample="false">
        </table>

    </context>
</generatorConfiguration>

1.2 编写配置文件:OrderMapper.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 namespace="com.xlb.ssm.mapper.OrderMapper" >
  <resultMap id="BaseResultMap" type="com.xlb.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>
  <sql id="Base_Column_List" >
    order_id, order_no
  </sql>
 
  <resultMap id="OrderVoMap" type="com.xlb.ssm.model.vo.OrderVo" >
    <result column="order_id" property="orderId"></result>
    <result column="order_no" property="orderNo"></result>
    <collection property="orderItems" ofType="com.xlb.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>
 
  <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.xlb.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.xlb.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.xlb.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.xlb.ssm.model.Order" >
    update t_hibernate_order
    set order_no = #{orderNo,jdbcType=VARCHAR}
    where order_id = #{orderId,jdbcType=INTEGER}
  </update>
</mapper>

1.3 建立Vo类

BookVo:

package com.xlb.ssm.model.vo;
 
import com.xlb.ssm.model.Order;
import com.xlb.ssm.model.OrderItem;
 
import java.util.List;
 
/**
 * @author 波哥
 * @site 2212371722
 * @company 波哥集团
 * @create  2022-08-16 8:15
 *
 * Vo类不仅仅包含当前表的信息、还能包含相关联的表的信息
 *
 * 当前订单会有一个或者多个订单项,多个订单先必须要集合进行接受
 */
public class OrderVo extends Order {
    //需求1:通过订单号查询本次订单的详情信息及对应的所有订单
    private List<OrderItem> orderItems;
 
    public List<OrderItem> getOrderItems() {
        return orderItems;
    }
 
    public void setOrderItems(List<OrderItem> orderItems) {
        this.orderItems = orderItems;
    }
}

BookItemVo:

package com.xlb.ssm.model.vo;
 
import com.xlb.ssm.model.Order;
import com.xlb.ssm.model.OrderItem;
import lombok.Data;
 
/**
 * @author 波哥
 * @site 2212371722
 * @company 波哥集团
 * @create  2022-08-16 8:35
 *
 * 某一个订单项一定属于某个订单的
 */
@Data
public class OrderItemVo extends OrderItem {
 
    private Order order;
 
    public Order getOrder() {
        return order;
    }
 
    public void setOrder(Order order) {
        this.order = order;
    }
}

添加@Data注释:省略了get、set、toString、构造方法。

SSM--关联关系映射_第1张图片
再然后分别在OrderMapper.java 和 OrderBiz 里面添加查询的方法

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

创建实现类OrderBizImpl

package com.xlb.ssm.biz.impl;
 
import com.xlb.ssm.biz.OrderBiz;
import com.xlb.ssm.mapper.OrderMapper;
import com.xlb.ssm.model.Order;
import com.xlb.ssm.model.vo.OrderVo;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
 
/**
 * @author 波哥
 * @site 2212371722
 * @company 波哥集团
 * @create  2022-08-16 9:52
 */
@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;
    }
}

测试类OrderBizImplTest

package com.xlb.ssm.biz.impl;
 
import com.xlb.ssm.biz.OrderBiz;
import com.xlb.ssm.model.Order;
import com.xlb.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.*;
 
/**
 * @author 波哥
 * @site 2212371722
 * @company 波哥集团
 * @create  2022-08-16 9:54
 */
@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations={"classpath:applicationContext-mybatis.xml"})
public class OrderBizImplTest {
 
    @Autowired
    private OrderBiz orderBiz;
 
    //需求1:通过订单号查询本次订单的详情信息及对应的所有订单
    //select * from t_hibernate_order o,t_hibernate_order_item oi
    //where o.order_id = oi.oid and o.order_id = 9
    @Test
    public void queryOrderVoByOrderId() {
        OrderVo orderVo = orderBiz.queryOrderVoByOrderId(9);
        System.out.println(orderVo);
        //打印订单项
        System.out.println(orderVo.getOrderItems());
    }
 
}

结果
SSM--关联关系映射_第2张图片

二、多对对

需求:根据书籍id,查询书籍信息以及所属类别信息;

2.1 逆向生成代码

配置要生成的实体类:generatorConfig.xml

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE generatorConfiguration PUBLIC "-//mybatis.org//DTD MyBatis Generator Configuration 1.0//EN"
        "http://mybatis.org/dtd/mybatis-generator-config_1_0.dtd" >
<generatorConfiguration>
    <!-- 引入配置文件 -->
    <properties resource="jdbc.properties"/>

    <!--指定数据库jdbc驱动jar包的位置-->
    <classPathEntry location="E:\\maven\\mavenjar\\mysql\\mysql-connector-java\\5.1.44\\mysql-connector-java-5.1.44.jar"/>

    <!-- 一个数据库一个context -->
    <context id="infoGuardian">
        <!-- 注释 -->
        <commentGenerator>
            <property name="suppressAllComments" value="true"/><!-- 是否取消注释 -->
            <property name="suppressDate" value="true"/> <!-- 是否生成注释代时间戳 -->
        </commentGenerator>

        <!-- jdbc连接 -->
        <jdbcConnection driverClass="${jdbc.driver}"
                        connectionURL="${jdbc.url}" userId="${jdbc.username}" password="${jdbc.password}"/>

        <!-- 类型转换 -->
        <javaTypeResolver>
            <!-- 是否使用bigDecimal, false可自动转化以下类型(Long, Integer, Short, etc.-->
            <property name="forceBigDecimals" value="false"/>
        </javaTypeResolver>

        <!-- 01 指定javaBean生成的位置 -->
        <!-- targetPackage:指定生成的model生成所在的包名 -->
        <!-- targetProject:指定在该项目下所在的路径  -->
        <javaModelGenerator targetPackage="com.xlb.ssm.model"
                            targetProject="src/main/java">
            <!-- 是否允许子包,即targetPackage.schemaName.tableName -->
            <property name="enableSubPackages" value="false"/>
            <!-- 是否对model添加构造函数 -->
            <property name="constructorBased" value="true"/>
            <!-- 是否针对string类型的字段在set的时候进行trim调用 -->
            <property name="trimStrings" value="false"/>
            <!-- 建立的Model对象是否 不可改变  即生成的Model对象不会有 setter方法,只有构造方法 -->
            <property name="immutable" value="false"/>
        </javaModelGenerator>

        <!-- 02 指定sql映射文件生成的位置 -->
        <sqlMapGenerator targetPackage="com.xlb.ssm.mapper"
                         targetProject="src/main/java">
            <!-- 是否允许子包,即targetPackage.schemaName.tableName -->
            <property name="enableSubPackages" value="false"/>
        </sqlMapGenerator>

        <!-- 03 生成XxxMapper接口 -->
        <!-- type="ANNOTATEDMAPPER",生成Java Model 和基于注解的Mapper对象 -->
        <!-- type="MIXEDMAPPER",生成基于注解的Java Model 和相应的Mapper对象 -->
        <!-- type="XMLMAPPER",生成SQLMap XML文件和独立的Mapper接口 -->
        <javaClientGenerator targetPackage="com.xlb.ssm.mapper"
                             targetProject="src/main/java" type="XMLMAPPER">
            <!-- 是否在当前路径下新加一层schema,false路径com.oop.eksp.user.model, true:com.oop.eksp.user.model.[schemaName] -->
            <property name="enableSubPackages" value="false"/>
        </javaClientGenerator>

        <!-- 配置表信息 -->
        <!-- schema即为数据库名 -->
        <!-- tableName为对应的数据库表 -->
        <!-- domainObjectName是要生成的实体类 -->
        <!-- enable*ByExample是否生成 example类 -->
        <!--<table schema="" tableName="t_book" domainObjectName="Book"-->
        <!--enableCountByExample="false" enableDeleteByExample="false"-->
        <!--enableSelectByExample="false" enableUpdateByExample="false">-->
        <!--&lt;!&ndash; 忽略列,不生成bean 字段 &ndash;&gt;-->
        <!--&lt;!&ndash; <ignoreColumn column="FRED" /> &ndash;&gt;-->
        <!--&lt;!&ndash; 指定列的java数据类型 &ndash;&gt;-->
        <!--&lt;!&ndash; <columnOverride column="LONG_VARCHAR_FIELD" jdbcType="VARCHAR" /> &ndash;&gt;-->
        <!--</table>-->

      <table schema="" tableName="t_hibernate_book" domainObjectName="Hbook"
               enableCountByExample="false" enableDeleteByExample="false"
               enableSelectByExample="false" enableUpdateByExample="false">
        </table>
 
        <table schema="" tableName="t_hibernate_category" domainObjectName="Category"
               enableCountByExample="false" enableDeleteByExample="false"
               enableSelectByExample="false" enableUpdateByExample="false">
        </table>
 
        <table schema="" tableName="t_hibernate_book_category" domainObjectName="HbookCategory"
               enableCountByExample="false" enableDeleteByExample="false"
               enableSelectByExample="false" enableUpdateByExample="false">
        </table>

————————————————
版权声明:本文为CSDN博主「_Leaf1217」的原创文章,遵循CC 4.0 BY-SA版权协议,转载请附上原文出处链接及本声明。
原文链接:https://blog.csdn.net/qq_63492318/article/details/126352928

    </context>
</generatorConfiguration>

2.2 创建Vo类

CategoryVo

package com.xlb.ssm.model.vo;
 
import com.xlb.ssm.model.Category;
import com.xlb.ssm.model.Hbook;
import lombok.Data;
import lombok.ToString;
 
import java.util.List;
 
/**
 * @author 波哥
 * @site 2212371722
 * @company 波哥集团
 * @create  2022-08-16 10:56
 */
@Data
public class CategoryVo extends Category {
    private List<Hbook> hbooks;
 
    public List<Hbook> getHbooks() {
        return hbooks;
    }
 
    public void setHbooks(List<Hbook> hbooks) {
        this.hbooks = hbooks;
    }
}

HbookVo

package com.xlb.ssm.model.vo;
 
import com.xlb.ssm.model.Category;
import com.xlb.ssm.model.Hbook;
import lombok.Data;
 
import java.util.List;
 
/**
 * @author 波哥
 * @site 2212371722
 * @company 波哥集团
 * @create  2022-08-16 10:56
 */
@Data
public class HbookVo extends Hbook {
    private List<Category> categories;
 
    public List<Category> getCategories() {
        return categories;
    }
 
    public void setCategories(List<Category> categories) {
        this.categories = categories;
    }
}

创建实现类:HbookCategoryBizImpl

package com.xlb.ssm.biz.impl;
 
import com.xlb.ssm.biz.HbookCategoryBiz;
import com.xlb.ssm.mapper.HbookCategoryMapper;
import com.xlb.ssm.model.HbookCategory;
import com.xlb.ssm.model.vo.CategoryVo;
import com.xlb.ssm.model.vo.HbookVo;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
 
/**
 * @author 波哥
 * @site 2212371722
 * @company 波哥集团
 * @create  2022-08-16 10:56
 */
@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);
    }
}

然后再创建测试类进行测试:HbookCategoryBizImplTest

package com.xlb.ssm.biz.impl;
 
import com.xlb.ssm.biz.HbookCategoryBiz;
import com.xlb.ssm.model.vo.CategoryVo;
import com.xlb.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.*;
 
/**
 * @author 波哥
 * @site 2212371722
 * @company 波哥集团
 * @create  2022-08-16 10:56
 */
@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);
    }
 
    @Test
    public void queryByCid() {
        CategoryVo categoryVo = hbookCategoryBiz.queryByCid(8);
        System.out.println(categoryVo);
    }
}

结果
SSM--关联关系映射_第3张图片

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