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">-->
<!--<!– 忽略列，不生成bean 字段 –>-->
<!--<!– <ignoreColumn column="FRED" /> –>-->
<!--<!– 指定列的java数据类型 –>-->
<!--<!– <columnOverride column="LONG_VARCHAR_FIELD" jdbcType="VARCHAR" /> –>-->
<!--</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;
/**
* 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;
/**
*
* 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。
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;
@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.*;
@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
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">-->
<!--<!– 忽略列，不生成bean 字段 –>-->
<!--<!– <ignoreColumn column="FRED" /> –>-->
<!--<!– 指定列的java数据类型 –>-->
<!--<!– <columnOverride column="LONG_VARCHAR_FIELD" jdbcType="VARCHAR" /> –>-->
<!--</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>
</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;
@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;
@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;
@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.*;
@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
到此这篇关于Java SMM框架关联关系映射示例讲解的文章就介绍到这了,更多相关SSM关联关系映射内容请搜索Devmax以前的文章或继续浏览下面的相关文章希望大家以后多多支持Devmax！