Java SMM框架關聯(lián)關系映射示例講解
一、一對多關聯(lián)關系
需求:通過訂單號查詢本次訂單的詳情信息以及對應的所有訂單
1.1 逆向生成代碼配置文件
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"/> <!--指定數(shù)據(jù)庫jdbc驅(qū)動jar包的位置--> <classPathEntry location="E:\\maven\\mavenjar\\mysql\\mysql-connector-java\\5.1.44\\mysql-connector-java-5.1.44.jar"/> <!-- 一個數(shù)據(jù)庫一個context --> <context id="infoGuardian"> <!-- 注釋 --> <commentGenerator> <property name="suppressAllComments" value="true"/><!-- 是否取消注釋 --> <property name="suppressDate" value="true"/> <!-- 是否生成注釋代時間戳 --> </commentGenerator> <!-- jdbc連接 --> <jdbcConnection driverClass="${jdbc.driver}" connectionURL="${jdbc.url}" userId="${jdbc.username}" password="${jdbc.password}"/> <!-- 類型轉換 --> <javaTypeResolver> <!-- 是否使用bigDecimal, false可自動轉化以下類型(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:指定在該項目下所在的路徑 --> <javaModelGenerator targetPackage="com.xlb.ssm.model" targetProject="src/main/java"> <!-- 是否允許子包,即targetPackage.schemaName.tableName --> <property name="enableSubPackages" value="false"/> <!-- 是否對model添加構造函數(shù) --> <property name="constructorBased" value="true"/> <!-- 是否針對string類型的字段在set的時候進行trim調(diào)用 --> <property name="trimStrings" value="false"/> <!-- 建立的Model對象是否 不可改變 即生成的Model對象不會有 setter方法,只有構造方法 --> <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"> <!-- 是否允許子包,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對象 --> <!-- type="MIXEDMAPPER",生成基于注解的Java Model 和相應的Mapper對象 --> <!-- type="XMLMAPPER",生成SQLMap XML文件和獨立的Mapper接口 --> <javaClientGenerator targetPackage="com.xlb.ssm.mapper" targetProject="src/main/java" type="XMLMAPPER"> <!-- 是否在當前路徑下新加一層schema,false路徑com.oop.eksp.user.model, true:com.oop.eksp.user.model.[schemaName] --> <property name="enableSubPackages" value="false"/> </javaClientGenerator> <!-- 配置表信息 --> <!-- schema即為數(shù)據(jù)庫名 --> <!-- tableName為對應的數(shù)據(jù)庫表 --> <!-- domainObjectName是要生成的實體類 --> <!-- enable*ByExample是否生成 example類 --> <!--<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數(shù)據(jù)類型 –>--> <!--<!– <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 編寫配置文件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類
BookVo:
package com.xlb.ssm.model.vo; import com.xlb.ssm.model.Order; import com.xlb.ssm.model.OrderItem; import java.util.List; /** * Vo類不僅僅包含當前表的信息、還能包含相關聯(lián)的表的信息 * * 當前訂單會有一個或者多個訂單項,多個訂單先必須要集合進行接受 */ public class OrderVo extends Order { //需求1:通過訂單號查詢本次訂單的詳情信息及對應的所有訂單 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; /** * * 某一個訂單項一定屬于某個訂單的 */ @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注釋:省略了get、set、toString、構造方法。
再然后分別在OrderMapper.java 和 OrderBiz 里面添加查詢的方法
OrderVo queryOrderVoByOrderId(@Param("orderId") Integer orderId);
創(chuàng)建實現(xiàn)類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; } }
測試類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:通過訂單號查詢本次訂單的詳情信息及對應的所有訂單 //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); //打印訂單項 System.out.println(orderVo.getOrderItems()); } }
結果
二、多對對
需求:根據(jù)書籍id,查詢書籍信息以及所屬類別信息;
2.1 逆向生成代碼
配置要生成的實體類: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"/> <!--指定數(shù)據(jù)庫jdbc驅(qū)動jar包的位置--> <classPathEntry location="E:\\maven\\mavenjar\\mysql\\mysql-connector-java\\5.1.44\\mysql-connector-java-5.1.44.jar"/> <!-- 一個數(shù)據(jù)庫一個context --> <context id="infoGuardian"> <!-- 注釋 --> <commentGenerator> <property name="suppressAllComments" value="true"/><!-- 是否取消注釋 --> <property name="suppressDate" value="true"/> <!-- 是否生成注釋代時間戳 --> </commentGenerator> <!-- jdbc連接 --> <jdbcConnection driverClass="${jdbc.driver}" connectionURL="${jdbc.url}" userId="${jdbc.username}" password="${jdbc.password}"/> <!-- 類型轉換 --> <javaTypeResolver> <!-- 是否使用bigDecimal, false可自動轉化以下類型(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:指定在該項目下所在的路徑 --> <javaModelGenerator targetPackage="com.xlb.ssm.model" targetProject="src/main/java"> <!-- 是否允許子包,即targetPackage.schemaName.tableName --> <property name="enableSubPackages" value="false"/> <!-- 是否對model添加構造函數(shù) --> <property name="constructorBased" value="true"/> <!-- 是否針對string類型的字段在set的時候進行trim調(diào)用 --> <property name="trimStrings" value="false"/> <!-- 建立的Model對象是否 不可改變 即生成的Model對象不會有 setter方法,只有構造方法 --> <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"> <!-- 是否允許子包,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對象 --> <!-- type="MIXEDMAPPER",生成基于注解的Java Model 和相應的Mapper對象 --> <!-- type="XMLMAPPER",生成SQLMap XML文件和獨立的Mapper接口 --> <javaClientGenerator targetPackage="com.xlb.ssm.mapper" targetProject="src/main/java" type="XMLMAPPER"> <!-- 是否在當前路徑下新加一層schema,false路徑com.oop.eksp.user.model, true:com.oop.eksp.user.model.[schemaName] --> <property name="enableSubPackages" value="false"/> </javaClientGenerator> <!-- 配置表信息 --> <!-- schema即為數(shù)據(jù)庫名 --> <!-- tableName為對應的數(shù)據(jù)庫表 --> <!-- domainObjectName是要生成的實體類 --> <!-- enable*ByExample是否生成 example類 --> <!--<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數(shù)據(jù)類型 –>--> <!--<!– <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 創(chuàng)建Vo類
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; } }
創(chuàng)建實現(xiàn)類: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); } }
然后再創(chuàng)建測試類進行測試: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); } }
結果
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