MyBatis--注解增删改查和级联查询

于 2019-11-30 13:16:52 发布
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分类专栏： Mybatis 文章标签： MyBatis 注解
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本文链接：https://blog.youkuaiyun.com/cold___play/article/details/103323422
本文详细介绍MyBatis注解的使用方法，包括Maven工程搭建、依赖配置、Pojo类定义、Mapper接口注解、多对一和多对多关联映射，以及配置文件解析。通过具体实例演示如何实现单表的增删改查操作，一对一、一对多和多对多关联映射的查询。

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Mybatis注解的使用实例

创建Maven工程及配置依赖

<?xml version="1.0" encoding="UTF-8"?>

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>

  <groupId>pers.zhang</groupId>
  <artifactId>MyBatisPro</artifactId>
  <version>1.0-SNAPSHOT</version>
  <packaging>war</packaging>

  <name>MyBatisPro Maven Webapp</name>
  <!-- FIXME change it to the project's website -->
  <url>http://www.example.com</url>

  <properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <maven.compiler.source>1.7</maven.compiler.source>
    <maven.compiler.target>1.7</maven.compiler.target>
  </properties>

  <dependencies>
    <dependency>
        <groupId>org.mybatis</groupId>
        <artifactId>mybatis</artifactId>
        <version>3.4.6</version>
    </dependency>
    <dependency>
      <groupId>log4j</groupId>
      <artifactId>log4j</artifactId>
      <version>1.2.17</version>
    </dependency>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>4.12</version>
      <scope>compile</scope>
    </dependency>

    <!--mysql驱动包-->
    <dependency>
      <groupId>mysql</groupId>
      <artifactId>mysql-connector-java</artifactId>
      <version>5.1.35</version>
    </dependency>
  </dependencies>

  <build>
    <!-- 编译java下的Mapper.xml -->
    <resources>
      <resource>
        <directory>src/main/java</directory>
        <includes>
          <include>**/*.xml</include>
        </includes>
      </resource>
    </resources>

    <finalName>MyBatisPro</finalName>
    <pluginManagement><!-- lock down plugins versions to avoid using Maven defaults (may be moved to parent pom) -->
      <plugins>
        <plugin>
          <artifactId>maven-clean-plugin</artifactId>
          <version>3.1.0</version>
        </plugin>
        <!-- see http://maven.apache.org/ref/current/maven-core/default-bindings.html#Plugin_bindings_for_war_packaging -->
        <plugin>
          <artifactId>maven-resources-plugin</artifactId>
          <version>3.0.2</version>
        </plugin>
        <plugin>
          <artifactId>maven-compiler-plugin</artifactId>
          <version>3.8.0</version>
        </plugin>
        <plugin>
          <artifactId>maven-surefire-plugin</artifactId>
          <version>2.22.1</version>
        </plugin>
        <plugin>
          <artifactId>maven-war-plugin</artifactId>
          <version>3.2.2</version>
        </plugin>
        <plugin>
          <artifactId>maven-install-plugin</artifactId>
          <version>2.5.2</version>
        </plugin>
        <plugin>
          <artifactId>maven-deploy-plugin</artifactId>
          <version>2.8.2</version>
        </plugin>
      </plugins>
    </pluginManagement>
  </build>
</project>

Pojo

public class AdminInfo {
    private int id;
    private String name;

    //关联属性
    private List<Functions> fs;
	//省略getter和setter
}

public class Functions {
    private int id;
    private String name;
    //...
}

public class Idcard {
    private int id;
    private String cno;
    //...
}

public class Person {
    private int id;
    private String name;
    private int age;
    private  String sex;
    //关联属性
    private  Idcard idcard;
    //...
}

public class ProductInfo {
    private int id;
    private String code;
    private String name;
    //关联属性
    private Type type;
    //...
}

public class Type {
    private int id;
    private String name;

    //关联属性集合
    private List<ProductInfo> pis;
    //...
}

public class UserInfo {
    private int id;
    private String userName;
    private String password;
    private String realName;
    private String sex;
    private String address;
    private String emial;
    private String regDate;
    private int status;
    //...
}

单表增删改查：UserInfoMapper

package pers.zhang.mapper;

import org.apache.ibatis.annotations.Delete;
import org.apache.ibatis.annotations.Insert;
import org.apache.ibatis.annotations.Select;
import org.apache.ibatis.annotations.Update;
import pers.zhang.pojo.UserInfo;

import java.util.List;

public interface UserInfoMapper {

    @Select("select * from user_info where id=#{id}")
    public UserInfo findUserInfoById(int id);

    @Select("select * from user_info where userName like CONCAT(CONCAT('%',#{userName}),'%')")
    public List<UserInfo> findUserInfoByUserName(String userName);

    @Insert("insert into user_info(userName, password)" +
            "values(#{userName}, #{password})")
    public int addUserInfo(UserInfo userInfo);

    @Update("update user_info set userName = #{userName}, password=#{password} where id = #{id}")
    public int updateUserInfo(UserInfo userInfo);

    @Delete("delete from user_info where id=#{id}")
    public int deleteUserInfo(int id);
}

一对一关联映射：IdcardMapper、PersonMapper

package pers.zhang.mapper;

import org.apache.ibatis.annotations.Select;
import pers.zhang.pojo.Idcard;

public interface IdcardMapper {
    //根据id查询身份证信息
    @Select("select * from idcard where id=#{id}")
    public Idcard findIdcardById(int id);
}

package pers.zhang.mapper;

import org.apache.ibatis.annotations.One;
import org.apache.ibatis.annotations.Result;
import org.apache.ibatis.annotations.Results;
import org.apache.ibatis.annotations.Select;
import pers.zhang.pojo.Person;

/**
 * @author zhang
 * @date 2019/11/30 - 10:54
 */
public interface PersonMapper {
    //根据id查询个人信息
    @Select("select * from person where id=#{id}")
    @Results({
            @Result(property = "idcard", column = "cid", one = @One(select = "pers.zhang.mapper.IdcardMapper.findIdcardById"))
    })
    public Person findPersonById(int id);
}

一对多关联映射：ProductInfoMapper、TypeMapper

package pers.zhang.mapper;

import org.apache.ibatis.annotations.One;
import org.apache.ibatis.annotations.Result;
import org.apache.ibatis.annotations.Results;
import org.apache.ibatis.annotations.Select;
import pers.zhang.pojo.ProductInfo;

import java.util.List;

public interface ProductInfoMapper {
    //根据类型编号查询所有信息
    @Select("select * from product_info where tid = #{tid}")
    List<ProductInfo> findProductInfoByTid(int tid);

    //根据商品编号获取商品信息
    @Select("select * from product_info where id = #{id}")
    @Results({
            @Result(property = "type", column = "tid", one = @One(select = "pers.zhang.mapper.TypeMapper.findTypeByTd"))
    })
    ProductInfo findProductInfoById(int id);
}


package pers.zhang.mapper;

import org.apache.ibatis.annotations.Many;
import org.apache.ibatis.annotations.Result;
import org.apache.ibatis.annotations.Results;
import org.apache.ibatis.annotations.Select;
import pers.zhang.pojo.Type;

public interface TypeMapper {
    //根据商品类型编号查询商品类型信息
    @Select("select * from type where id = #{id}")
    @Results({
            @Result(id = true, property = "id", column = "id"),
            @Result(property = "name", column = "name"),
            @Result(property = "pis", column = "id", many = @Many(select = "pers.zhang.mapper.ProductInfoMapper.findProductInfoByTid"))
    })
    Type findTypeById(int id);
}

多对多映射关联：FunctionsMapper、AdminInfoMapper

package pers.zhang.mapper;

import org.apache.ibatis.annotations.Select;
import pers.zhang.pojo.Functions;

import java.util.List;

public interface FunctionsMapper {
    //根据管理员id查询管理员信息
    @Select("select * from functions where id in" +
            "(select fid from powers where aid = #{id})")
    List<Functions> findFunctionsByAid(int aid);
}


package pers.zhang.mapper;


import org.apache.ibatis.annotations.Many;
import org.apache.ibatis.annotations.Result;
import org.apache.ibatis.annotations.Results;
import org.apache.ibatis.annotations.Select;
import pers.zhang.pojo.AdminInfo;

public interface AdminInfoMapper {
    //根据管理员id查询管理员信息
    @Select("select * from admin_info where id = #{id}")
    @Results({
            @Result(property = "id", column = "id", id = true),
            @Result(property = "name", column = "name"),
            @Result(property = "fs", column = "id", many = @Many(select = "pers.zhang.mapper.FunctionsMapper.findFunctionsByAid"))
    })
    public AdminInfo findAdminInfoById(int id);
}

配置Mybatis

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration
PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
	<!-- 加载属性文件 -->
	<properties resource="db.properties"/>
	<!-- 给包中的类注册别名 -->
	<typeAliases>
		<package name="pers.zhang.pojo" />
	</typeAliases>
	<!-- 配置environment环境 -->
	<environments default="development">
		<!-- 配置一个id为development的环境 -->
		<environment id="development">
			<!-- 使用JDBC事务 -->
			<transactionManager type="JDBC" />
			<!-- 数据库连接池 -->
			<dataSource type="POOLED">
				<property name="driver" value="${jdbc.driver}" />
				<property name="url" value="${jdbc.url}" />
				<property name="username" value="${jdbc.username}" />
				<property name="password" value="${jdbc.password}" />
			</dataSource>
		</environment>
	</environments>
	<!-- 引用映射文件 -->
	<mappers>
		<mapper class="pers.zhang.mapper.UserInfoMapper"/>
		<mapper class="pers.zhang.mapper.PersonMapper"/>
		<mapper class="pers.zhang.mapper.IdcardMapper"/>
		<mapper class="pers.zhang.mapper.TypeMapper"/>
		<mapper class="pers.zhang.mapper.ProductInfoMapper"/>
		<mapper class="pers.zhang.mapper.AdminInfoMapper"/>
		<mapper class="pers.zhang.mapper.FunctionsMapper"/>
	</mappers>
</configuration>

测试类MyTest：

package pers.zhang.test;

import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;
import org.junit.experimental.theories.suppliers.TestedOn;
import org.omg.PortableInterceptor.AdapterManagerIdHelper;
import pers.zhang.mapper.AdminInfoMapper;
import pers.zhang.mapper.PersonMapper;
import pers.zhang.mapper.TypeMapper;
import pers.zhang.mapper.UserInfoMapper;
import pers.zhang.pojo.AdminInfo;
import pers.zhang.pojo.Person;
import pers.zhang.pojo.Type;
import pers.zhang.pojo.UserInfo;

import java.io.IOException;
import java.io.InputStream;
import java.util.List;

/**
 * @author zhang
 * @date 2019/11/30 - 10:10
 */
public class MyTest {
    private SqlSessionFactory sqlSessionFactory;
    private SqlSession sqlSession;

    @Before
    public void init(){
        //读取mybatis配置文件
        String resource = "mybatis-config.xml";
        InputStream inputStream;
        try {
            //得到配置文件流
            InputStream in = Resources.getResourceAsStream(resource);
            //根据配置文件创建session工厂
            sqlSessionFactory = new SqlSessionFactoryBuilder().build(in);
            sqlSession = sqlSessionFactory.openSession();
        }catch (IOException e){
            e.printStackTrace();
        }
    }


    @After
    public void destroy(){
        //提交事务
        sqlSession.commit();
        sqlSession.close();
    }


    //根据id查询
    @Test
    public void testFindUserInfoById(){
        UserInfoMapper mapper = sqlSession.getMapper(UserInfoMapper.class);
        UserInfo userInfo = mapper.findUserInfoById(1);
        System.out.println(userInfo);
    }

    //根据用户名模糊查询
    @Test
    public void testFindUserInfoByUserName(){
        List<UserInfo> list = sqlSession.getMapper(UserInfoMapper.class).findUserInfoByUserName("m");
        for(UserInfo userInfo : list){
            System.out.println(userInfo);
        }
    }

    //添加用户
    @Test
    public void testAddUserInfo(){
        UserInfo userInfo = new UserInfo();
        userInfo.setUserName("mybatis1");
        userInfo.setPassword("1123456");
        int result = sqlSession.getMapper(UserInfoMapper.class).addUserInfo(userInfo);
        if (result > 0)
            System.out.println("插入成功");
        else
            System.out.println("插入失败！");
    }

    //修改用户
    @Test
    public void testUpdateUserInfo(){
        UserInfo userInfo = sqlSession.getMapper(UserInfoMapper.class).findUserInfoById(8);
        userInfo.setPassword("123123");
        int result = sqlSession.getMapper(UserInfoMapper.class).updateUserInfo(userInfo);
        if(result > 0){
            System.out.println("更新成功！");
            System.out.println(userInfo);
        }else{
            System.out.println("更新失败！");
        }
    }


    //删除用户
    @Test
    public void testDeleteUserInfo(){
        int result = sqlSession.getMapper(UserInfoMapper.class).deleteUserInfo(8);
        if(result > 0)
            System.out.println("成功删除了" + result + "条记录。");
        else{
            System.out.println("删除失败！");
        }
    }


    //测试一对一映射
    @Test
    public void testOne2One(){
        Person person = sqlSession.getMapper(PersonMapper.class).findPersonById(1);
        System.out.println(person);
    }

    //测试一对多关联映射
    @Test
    public void testOne2Many(){
        Type type = sqlSession.getMapper(TypeMapper.class).findTypeById(1);
        System.out.println(type);
    }

    //测试多对多关联映射
    @Test
    public void testMany2Many(){
        AdminInfo adminInfo = sqlSession.getMapper(AdminInfoMapper.class).findAdminInfoById(1);
        System.out.println(adminInfo);
    }
}
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