Table of contents
1. Introduction to relationship mapping
2. One-to-one & one-to-many relationship configuration in Mybatis
1. Import relevant database tables
resultType "java.yutils.Map" method:
3. Case deployment preparation
3.1 Generate entity classes corresponding to the required database
genreatorConfig.xml configures entity class information
3. Demonstration of related relationship cases
3.1 One-to-many association relationship case demonstration
Interface class and interface implementation class code
3.2 One-to-one association relationship case demonstration
Interface class and interface implementation class code
3.3 Many-to-many association relationship case demonstration
Interface class and interface implementation class code
Preface
In the last blog, I shared with veterans about the integration of Mybatis and Spring, and realized the convenience and charm that Spring brings to Mybatis. Today I will take you veterans into the world of Mybatis relationship mapping, and let us understand the shock that this world brings to us. I hope that veterans can gain something.
1. Introduction to relationship mapping
1. Concept
Mybatis' association mapping is a technology that maps associations between database tables to Java objects . It maps the columns of the database table to the properties of the Java object through configuration files or annotations , thereby realizing data interaction between the object and the database . This mapping relationship can be one-to-one, one-to-many, many-to-one or many-to-many . Through Mybatis's association mapping, we can easily perform database operations without manually writing SQL statements.
2. Features
Characteristics of Mybatis association relationship mapping
Feature Description: Flexible association mapping: Mybatis's association mapping is very flexible. Various types of associations can be defined according to actual needs, including one-to-one, one-to-many, many-to-one, and many-to-many. Convenient configuration for developers: Through the Mybatis configuration file or annotations, association mapping can be easily defined without writing cumbersome SQL statements, reducing the workload of developers. Conducive to project performance optimization Mybatis's association mapping can be lazy loaded and delayed loaded, that is, the associated objects are queried only when needed, which improves system performance and reduces unnecessary query operations. Improve efficiency and reduce database access pressure. Mybatis supports first-level cache and second-level cache, which can cache associated objects, improve query efficiency, and reduce database access pressure. Make the project extensible. Mybatis's association mapping can meet customized development of specific needs through custom TypeHandler and other extension points.
3. Usage scenarios
Object relational mapping (ORM) : Mybatis can map database tables to Java objects to facilitate object persistence operations and simplify the writing and management of database operations.
Complex queries: Through association relationship mapping, complex query operations can be easily performed, including multi-table associated queries, nested queries, etc., reducing the workload of manually writing SQL statements.
Database transaction management: Mybatis's association mapping can be used in conjunction with database transaction management to achieve data consistency and integrity.
Cache management: Through association relationship mapping, cache management can be easily performed, query efficiency can be improved, and database access pressure can be reduced.
Distributed system: In a distributed system, Mybatis's association mapping can help achieve data consistency and distributed transaction management.
2. One-to-one & one-to-many relationship configuration in Mybatis
1. Import relevant database tables
The above are the database tables required for our case demonstration.
2. Multi-table query
resultType "java.yutils.Map" method :
This method of multi-table query is not recommended for use in company projects. It is beneficial for your own developers, but it is disadvantageous for corporate development and project R&D teams.
Benefits: When customer needs change (Requirement 1-->Requirement 2 (add fields)-->Requirement 3 (add fields)), no matter how the customer needs change, my code will not change. Just add a field.
Disadvantages: This method is not conducive to later maintenance and expansion in the company or R&D team.
3. Case deployment preparation
3.1 Generate entity classes corresponding to the required database
genreatorConfig.xml configures entity class information
<?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="D:\\MYsoftware\\Maven\\mvn_repsoitory\\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.yx.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.yx.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.yx.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_mvc_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>
<!-- 配置要生成的实体类对应的数据库表-->
<table schema="" tableName="t_hibernate_book" domainObjectName="HBook"
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>
<table schema="" tableName="t_hibernate_category" domainObjectName="HCategory"
enableCountByExample="false" enableDeleteByExample="false"
enableSelectByExample="false" enableUpdateByExample="false">
</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>
operate
3. Demonstration of related relationship cases
3.1 One-to-many association relationship case demonstration
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.yx.mapper.OrderMapper" >
<resultMap id="BaseResultMap" type="com.yx.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.yx.vo.OrderVo" >
<result column="order_id" property="orderId"></result>
<result column="order_no" property="orderNo"></result>
<collection property="orderItems" ofType="com.yx.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="selectByOid" 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 =#{oid }
</select>
</mapper>OrderMapper.java
package com.yx.mapper;
import com.yx.model.Order;
import com.yx.vo.OrderVo;
import org.apache.ibatis.annotations.Param;
public interface OrderMapper {
OrderVo selectByOid(@Param("oid") Integer oid);
}Entity class code
package com.yx.model;
import lombok.ToString;
@ToString
public class Order {
private Integer orderId;
private String orderNo;
public Order(Integer orderId, String orderNo) {
this.orderId = orderId;
this.orderNo = orderNo;
}
public Order() {
super();
}
public Integer getOrderId() {
return orderId;
}
public void setOrderId(Integer orderId) {
this.orderId = orderId;
}
public String getOrderNo() {
return orderNo;
}
public void setOrderNo(String orderNo) {
this.orderNo = orderNo;
}
}
//=========================以上是Order实体类代码========================================
//=========================以下是OrderItem实体类代码========================================
package com.yx.model;
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;
}
}Interface class and interface implementation class code
package com.yx.biz;
import com.yx.vo.OrderVo;
/**
* @author 君易--鑨
* @site www.yangxin.com
* @company 木易
* @create 2023-09-04 10:14
*/
public interface OrderBiz {
OrderVo selectByOid(Integer oid);
}
//============================以上是接口类代码==========================
//============================以下是接口实现类代码======================
package com.yx.biz.impl;
import com.yx.biz.OrderBiz;
import com.yx.mapper.OrderMapper;
import com.yx.vo.OrderVo;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
/**
* @author 君易--鑨
* @site www.yangxin.com
* @company 木易
* @create 2023-09-04 10:15
*/
@Service
public class OrderBizImpl implements OrderBiz {
@Autowired
private OrderMapper orderMapper;
@Override
public OrderVo selectByOid(Integer oid) {
return orderMapper.selectByOid(oid);
}
}
OrderVo class code
package com.yx.vo;
import com.yx.model.Order;
import com.yx.model.OrderItem;
import java.util.ArrayList;
import java.util.List;
/**
* @author 君易--鑨
* @site www.yangxin.com
* @company 木易
* @create 2023-09-04 9:05
*/
public class OrderVo extends Order {
private List<OrderItem> orderItems =new ArrayList<OrderItem>();
public List<OrderItem> getOrderItems() {
return orderItems;
}
public void setOrderItems(List<OrderItem> orderItems) {
this.orderItems = orderItems;
}
}
Test code
package com.yx.biz.impl;
import com.yx.biz.OrderBiz;
import com.yx.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;
/**
* @author 君易--鑨
* @site www.yangxin.com
* @company 木易
* @create 2023-09-04 10:19
* 订单测试类
*/
@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations={"classpath:spring-context.xml"})
public class OrderBizImplTest {
@Autowired
private OrderBiz orderBiz;
@Test
public void selectByOid() {
OrderVo orderVo = orderBiz.selectByOid(7);
System.out.println(orderVo);
orderVo.getOrderItems().forEach(System.out::println);
}
}Test Results
3.2 One-to-one association relationship case demonstration
OrderItemMapper.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.yx.mapper.OrderItemMapper" >
<resultMap id="BaseResultMap" type="com.yx.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>
<sql id="Base_Column_List" >
order_item_id, product_id, quantity, oid
</sql>
<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>
<resultMap id="OrderItemVoMap" type="com.yx.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.yx.model.Order">
<result column="order_id" property="orderId"></result>
<result column="order_no" property="orderNo"></result>
</association>
</resultMap>
<select id="selectByOrderItemId" 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=#{oiid}
</select>
</mapper>OrderItemMapper.java
package com.yx.mapper;
import com.yx.model.OrderItem;
import com.yx.vo.OrderItemVo;
import org.apache.ibatis.annotations.Param;
public interface OrderItemMapper {
OrderItemVo selectByOrderItemId(@Param("oiid") Integer oiid);
}Entity class code
package com.yx.model;
import lombok.ToString;
@ToString
public class Order {
private Integer orderId;
private String orderNo;
public Order(Integer orderId, String orderNo) {
this.orderId = orderId;
this.orderNo = orderNo;
}
public Order() {
super();
}
public Integer getOrderId() {
return orderId;
}
public void setOrderId(Integer orderId) {
this.orderId = orderId;
}
public String getOrderNo() {
return orderNo;
}
public void setOrderNo(String orderNo) {
this.orderNo = orderNo;
}
}
//=========================以上是Order实体类代码========================================
//=========================以下是OrderItem实体类代码========================================
package com.yx.model;
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;
}
}OrderItemVo class code
package com.yx.vo;
import com.yx.model.Order;
import com.yx.model.OrderItem;
/**
* @author 君易--鑨
* @site www.yangxin.com
* @company 木易
* @create 2023-09-04 11:07
*/
public class OrderItemVo extends OrderItem {
private Order order;
public Order getOrder() {
return order;
}
public void setOrder(Order order) {
this.order = order;
}
}
Interface class and interface implementation class code
package com.yx.biz;
import com.yx.vo.OrderItemVo;
import org.apache.ibatis.annotations.Param;
/**
* @author 君易--鑨
* @site www.yangxin.com
* @company 木易
* @create 2023-09-04 11:10
*/
public interface OrderItemBiz {
OrderItemVo selectByOrderItemId(@Param("oiid") Integer oiid);
}
//============================以上是接口类代码==========================
//============================以下是接口实现类代码======================
package com.yx.biz.impl;
import com.yx.biz.OrderItemBiz;
import com.yx.mapper.OrderItemMapper;
import com.yx.vo.OrderItemVo;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
/**
* @author 君易--鑨
* @site www.yangxin.com
* @company 木易
* @create 2023-09-04 11:11
*/
@Service
public class OrderItemBizImpl implements OrderItemBiz {
@Autowired
private OrderItemMapper orderItemMapper;
@Override
public OrderItemVo selectByOrderItemId(Integer oiid) {
return orderItemMapper.selectByOrderItemId(oiid);
}
}
Test code
package com.yx.biz.impl;
import com.yx.biz.OrderItemBiz;
import com.yx.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;
/**
* @author 君易--鑨
* @site www.yangxin.com
* @company 木易
* @create 2023-09-04 11:13
* 测试类
*/
@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations={"classpath:spring-context.xml"})
public class OrderItemBizImplTest {
@Autowired
private OrderItemBiz orderItemBiz;
@Test
public void selectByOrderItemId() {
OrderItemVo orderItemVo = orderItemBiz.selectByOrderItemId(27);
System.out.println(orderItemVo);
System.out.println(orderItemVo.getOrder());
}
}Test Results
3.3 Many-to-many association relationship case demonstration
HBookMapper.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.yx.mapper.HBookMapper" >
<resultMap id="BaseResultMap" type="com.yx.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>
<resultMap id="HBookVoMap" type="com.yx.vo.HBookVo">
<result column="book_id" property="bookId"></result>
<result column="book_name" property="bookName"></result>
<result column="price" property="price"></result>
<collection property="categories" ofType="com.yx.model.HCategory">
<result column="category_id" property="categoryId"></result>
<result column="category_name" property="categoryName"></result>
</collection>
</resultMap>
<!-- 根据书籍的id查询出书籍的信息即所属类别-->
<select id="selectByBookId" 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=#{bid}
</select>
</mapper>HBookMapper.java
package com.yx.mapper;
import com.yx.model.HBook;
import com.yx.vo.HBookVo;
import org.apache.ibatis.annotations.Param;
public interface HBookMapper {
HBookVo selectByBookId(@Param("bid") Integer bid);
}Entity class code
package com.yx.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;
}
}
//==========================以上是HBook实体类代码==========================================
==========================以下是HCategory实体类代码==========================================
package com.yx.model;
import lombok.ToString;
@ToString
public class HCategory {
private Integer categoryId;
private String categoryName;
public HCategory(Integer categoryId, String categoryName) {
this.categoryId = categoryId;
this.categoryName = categoryName;
}
public HCategory() {
super();
}
public Integer getCategoryId() {
return categoryId;
}
public void setCategoryId(Integer categoryId) {
this.categoryId = categoryId;
}
public String getCategoryName() {
return categoryName;
}
public void setCategoryName(String categoryName) {
this.categoryName = categoryName;
}
}HBookVo code
package com.yx.vo;
import com.yx.model.HBook;
import com.yx.model.HCategory;
import java.util.List;
/**
* @author 君易--鑨
* @site www.yangxin.com
* @company 木易
* @create 2023-09-04 11:34
*/
public class HBookVo extends HBook {
private List<HCategory> categories;
public List<HCategory> getCategories() {
return categories;
}
public void setCategories(List<HCategory> categories) {
this.categories = categories;
}
}
Interface class and interface implementation class code
package com.yx.biz;
import com.yx.vo.HBookVo;
/**
* @author 君易--鑨
* @site www.yangxin.com
* @company 木易
* @create 2023-09-04 11:41
*/
public interface HBookBiz {
HBookVo selectByBookId(Integer bid);
}
//======================以上是接口类代码===================================
//======================以下是接口实现类代码===============================
package com.yx.biz.impl;
import com.yx.biz.HBookBiz;
import com.yx.mapper.HBookMapper;
import com.yx.vo.HBookVo;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
/**
* @author 君易--鑨
* @site www.yangxin.com
* @company 木易
* @create 2023-09-04 11:42
*/
@Service
public class HBookBizImpl implements HBookBiz {
@Autowired
private HBookMapper hBookMapper;
@Override
public HBookVo selectByBookId(Integer bid) {
return hBookMapper.selectByBookId(bid);
}
}
Test code
package com.yx.biz.impl;
import com.yx.biz.HBookBiz;
import com.yx.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;
/**
* @author 君易--鑨
* @site www.yangxin.com
* @company 木易
* @create 2023-09-04 11:43
*/
@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations={"classpath:spring-context.xml"})
public class HBookBizImplTest {
@Autowired
private HBookBiz hBookBiz;
@Test
public void selectByBookId() {
HBookVo hBookVo =this.hBookBiz.selectByBookId(8);
System.out.println(hBookVo);
hBookVo.getCategories().forEach(System.out::println);
}
}Test Results
