目录

一、整合Mybatis

配置文件

pom.xml

 application.yml

jdbc.properties

generatorConfig.xml

启动类

测试

二、整合Mybatis-plus

Mybatis-plus

新建项目

pom.xml

application.yml

在项目导入mybatis-plus的代码生成的类

 完成基本增删改查方法开发

 三、Mybatisplus中使用Mybatis实现多表连查的功能

一、整合Mybatis

确保项目启动成功

配置文件

pom.xml

修改mysql版本

        mysqlmysql-connector-java5.1.44

            org.mybatis.generatormybatis-generator-maven-plugin1.3.2mysqlmysql-connector-java5.1.44true

 application.yml

mybatis:mapper-locations: classpath:mappers/**/*.xmltype-aliases-package: com.maomao.pringbootmybatis.model
server:port: 8082
spring:application:name: spbootmybatisdatasource:driver-class-name: com.mysql.jdbc.Driverurl: jdbc:mysql://localhost:3306/mybatis_ssm?useUnicode=true&characterEncoding=UTF-8password: 123456username: root

jdbc.properties

jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/mybatis_ssm?useUnicode=true&characterEncoding=UTF-8
jdbc.username=root
jdbc.password=123456

generatorConfig.xml

启动类

package com.maomao.spbootmybatis;import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.transaction.annotation.EnableTransactionManagement;//完成对mapper接口的扫描
@MapperScan("com.maomao.spbootmybatis.mapper")
//开启对事物的管理
@EnableTransactionManagement
@SpringBootApplication
public class SpbootmybatisApplication {public static void main(String[] args) {SpringApplication.run(SpbootmybatisApplication.class, args);}}

测试

利用Eolink进行测试

二、整合Mybatis-plus

Mybatis-plus

官网

MyBatis-Plus

①企业中大量使用

②减少*Mapper.xml中的SQL编写

③与若依相比，略为繁琐，但是可移植性极强

新建项目

勾选五个组件：

lombok、web、jdbc、mybatis-plus、MySQL driver

pom.xml

4.0.0com.maomaospringbootmp0.0.1-SNAPSHOTspringbootmpDemo project for Spring Boot1.8UTF-8UTF-82.3.7.RELEASEorg.springframework.bootspring-boot-starter-jdbcorg.springframework.bootspring-boot-starter-webcom.baomidoumybatis-plus-boot-starter3.4.2com.baomidoumybatis-plus-generator3.4.1org.freemarkerfreemarker2.3.31mysqlmysql-connector-java5.1.44org.projectlomboklomboktrueorg.springframework.bootspring-boot-starter-testtestorg.junit.vintagejunit-vintage-enginecom.baomidoumybatis-plus-core3.4.2compileorg.springframework.bootspring-boot-dependencies${spring-boot.version}pomimportorg.apache.maven.pluginsmaven-compiler-plugin3.8.11.81.8UTF-8org.springframework.bootspring-boot-maven-plugin2.3.7.RELEASEcom.maomao.springbootmp.SpringbootmpApplicationrepackagerepackage

application.yml

server:port: 8082
spring:application:name: springbootmpdatasource:driver-class-name: com.mysql.jdbc.Driverurl: jdbc:mysql://localhost:3306/mybatis_ssm?useUnicode=true&characterEncoding=UTF-8password: 123456username: root
logging:level:com.maomao.springbootmp: debug
mybatis-plus:mapper-locations: classpath:mappers/**/*.xmltype-aliases-package: com.maomao.springbootmp.book.model

在项目导入mybatis-plus的代码生成的类

copy官网

注意事项：

（1）需要更改代码生成的module名

（2）需要设置父包的位置

（3）要预先创建好mappers的文件夹

MPGenerator.java

package com.maomao.springbootmp.mp;import com.baomidou.mybatisplus.annotation.DbType;
import com.baomidou.mybatisplus.annotation.IdType;
import com.baomidou.mybatisplus.core.exceptions.MybatisPlusException;
import com.baomidou.mybatisplus.core.toolkit.StringPool;
import com.baomidou.mybatisplus.core.toolkit.StringUtils;
import com.baomidou.mybatisplus.generator.AutoGenerator;
import com.baomidou.mybatisplus.generator.InjectionConfig;
import com.baomidou.mybatisplus.generator.config.*;
import com.baomidou.mybatisplus.generator.config.po.TableInfo;
import com.baomidou.mybatisplus.generator.config.rules.NamingStrategy;
import com.baomidou.mybatisplus.generator.engine.FreemarkerTemplateEngine;import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;/*** mybatis-plus代码生成*/
public class MPGenerator {/*** 
* 读取控制台内容* 
*/public static String scanner(String tip) {Scanner scanner = new Scanner(System.in);StringBuilder help = new StringBuilder();help.append("请输入" + tip);System.out.println(help.toString());if (scanner.hasNext()) {String ipt = scanner.next();if (StringUtils.isNotBlank(ipt)) {if ("quit".equals(ipt)) return "";return ipt;}}throw new MybatisPlusException("请输入正确的" + tip + "！");}public static void main(String[] args) {// 代码生成器AutoGenerator mpg = new AutoGenerator();// 1.全局配置GlobalConfig gc = new GlobalConfig();
//        System.getProperty("user.dir")指的是工作区间，就是Springboot01String projectPath = System.getProperty("user.dir") + "/springbootmp";System.out.println(projectPath);gc.setOutputDir(projectPath + "/src/main/java");gc.setOpen(false);gc.setBaseResultMap(true);//生成BaseResultMapgc.setActiveRecord(false);// 不需要ActiveRecord特性的请改为falsegc.setEnableCache(false);// XML 二级缓存gc.setBaseResultMap(true);// XML ResultMapgc.setBaseColumnList(true);// XML columList//gc.setSwagger2(true); //实体属性 Swagger2 注解gc.setAuthor("maomao");// 自定义文件命名，注意 %s 会自动填充表实体属性！gc.setMapperName("%sMapper");gc.setXmlName("%sMapper");gc.setServiceName("%sService");gc.setServiceImplName("%sServiceImpl");gc.setControllerName("%sController");gc.setIdType(IdType.AUTO);mpg.setGlobalConfig(gc);// 2.数据源配置DataSourceConfig dsc = new DataSourceConfig();dsc.setDbType(DbType.MYSQL);dsc.setUrl("jdbc:mysql://localhost:3306/mybatis_ssm?useUnicode=true&characterEncoding=UTF-8");dsc.setDriverName("com.mysql.jdbc.Driver");dsc.setUsername("root");dsc.setPassword("123456");mpg.setDataSource(dsc);// 3.包配置PackageConfig pc = new PackageConfig();String moduleName = scanner("模块名(quit退出，表示没有模块名)");if (StringUtils.isNotBlank(moduleName)) {pc.setModuleName(moduleName);}
//        设置父包pc.setParent("com.maomao.springbootmp").setMapper("mapper").setService("service").setController("controller").setEntity("model");mpg.setPackageInfo(pc);// 4.自定义配置InjectionConfig cfg = new InjectionConfig() {@Overridepublic void initMap() {// to do nothing}};// 如果模板引擎是 freemarkerString templatePath = "/templates/mapper.xml.ftl";// 自定义输出配置List focList = new ArrayList<>();// 自定义配置会被优先输出focList.add(new FileOutConfig(templatePath) {@Overridepublic String outputFile(TableInfo tableInfo) {// 自定义输出文件名 ， 如果你 Entity 设置了前后缀、此处注意 xml 的名称会跟着发生变化！！if (StringUtils.isNotBlank(pc.getModuleName())) {return projectPath + "/src/main/resources/mappers/" + pc.getModuleName() + "/" + tableInfo.getEntityName() + "Mapper" + StringPool.DOT_XML;} else {return projectPath + "/src/main/resources/mappers/" + tableInfo.getEntityName() + "Mapper" + StringPool.DOT_XML;}}});cfg.setFileOutConfigList(focList);mpg.setCfg(cfg);// 配置模板TemplateConfig templateConfig = new TemplateConfig();templateConfig.setXml(null);mpg.setTemplate(templateConfig);// 5.策略配置StrategyConfig strategy = new StrategyConfig();// 表名生成策略(下划线转驼峰命名)strategy.setNaming(NamingStrategy.underline_to_camel);// 列名生成策略(下划线转驼峰命名)strategy.setColumnNaming(NamingStrategy.underline_to_camel);// 是否启动Lombok配置strategy.setEntityLombokModel(true);// 是否启动REST风格配置strategy.setRestControllerStyle(true);// 自定义实体父类strategy.setSuperEntityClass("com.baomidou.mybatisplus.extension.activerecord.Model");// 自定义service父接口strategy.setSuperServiceClass("com.baomidou.mybatisplus.extension.service.IService");// 自定义service实现类strategy.setSuperServiceImplClass("com.baomidou.mybatisplus.extension.service.impl.ServiceImpl");// 自定义mapper接口strategy.setSuperMapperClass("com.baomidou.mybatisplus.core.mapper.BaseMapper");strategy.setSuperEntityColumns("id");// 写于父类中的公共字段plusstrategy.setSuperEntityColumns("id");strategy.setInclude(scanner("表名，多个英文逗号分割").split(","));strategy.setControllerMappingHyphenStyle(true);//表名前缀(可变参数)：“t_”或”“t_模块名”，例如：t_user或t_sys_userstrategy.setTablePrefix("t_", "t_sys_");//strategy.setTablePrefix(scanner("请输入表前缀"));mpg.setStrategy(strategy);mpg.setTemplateEngine(new FreemarkerTemplateEngine());// 执行mpg.execute();}
}

运行：

mybatis-plus接口的讲解 

（1）basemapper/baseservice都已经封装好了基本的增删改查及基本使用

（2）QueryWrapper的使用，可以构建查询条件，减少配置文件xml的sql编写

 完成基本增删改查方法开发

MvcBookController.java

package com.maomao.springbootmp.book.controller;import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.maomao.springbootmp.book.model.MvcBook;
import com.maomao.springbootmp.book.service.MvcBookService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PutMapping;
import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.bind.annotation.RestController;import java.util.List;/*** 
*  前端控制器* 
** @author maomao* @since 2022-12-02*/
@RestController
@RequestMapping("/mp")
public class MvcBookController {@Autowiredprivate MvcBookService bookService;//    查询所有@GetMapping("/list")public List list(){return bookService.list();}//    按条件查询@GetMapping("/listByCondition")public List listByCondition(MvcBook book){
//        如果使用的是Mybatis，那么我们需要写SQL语句，而MP不需要QueryWrapper qw=new QueryWrapper();qw.like("bname",book.getBname());return bookService.list();}//    查询单个@GetMapping("/get")public MvcBook get(MvcBook book){return bookService.getById(book.getBid());}//    增加@PutMapping("/add")public boolean add(MvcBook book){return bookService.save(book);}//    删除@PutMapping("/delete")public boolean delete(MvcBook book){return bookService.removeById(book.getBid());}//    修改@PutMapping("/update")public boolean update(MvcBook book){return bookService.saveOrUpdate(book);}}

测试

 三、Mybatisplus中使用Mybatis实现多表连查的功能

 用户、角色、用户角色中间表连表查询的案例

MvcBookMappper.xml

bid, bname, priceSELECT u.username,r.rolename FROM t_shiro_user u,t_shiro_user_role ur,t_shiro_role rwhere u.userid = ur.userid and ur.roleid = r.roleidand u.username = #{username}

MvcBookMapper.java

package com.maomao.springbootmp.book.mapper;import com.maomao.springbootmp.book.model.MvcBook;
import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import org.springframework.stereotype.Repository;import java.util.List;
import java.util.Map;/*** 
*  Mapper 接口* 
** @author maomao* @since 2022-12-02*/
@Repository
public interface MvcBookMapper extends BaseMapper {List

MvcBookService.java

package com.maomao.springbootmp.book.service;import com.maomao.springbootmp.book.model.MvcBook;
import com.baomidou.mybatisplus.extension.service.IService;import java.util.List;
import java.util.Map;/*** 
*  服务类* 
** @author maomao* @since 2022-12-02*/
public interface MvcBookService extends IService {List

MvcBookServiceImpl.java

package com.maomao.springbootmp.book.service.impl;import com.maomao.springbootmp.book.model.MvcBook;
import com.maomao.springbootmp.book.mapper.MvcBookMapper;
import com.maomao.springbootmp.book.service.MvcBookService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;import java.util.List;
import java.util.Map;/*** 
*  服务实现类* 
** @author maomao* @since 2022-12-02*/
@Service
public class MvcBookServiceImpl extends ServiceImpl implements MvcBookService {@Autowiredprivate MvcBookMapper bookMapper;@Overridepublic List

MvcBookController.java

 //多表联查 ，用户姓名对应角色的功能，论证mybatis是一样可以使用mybatis功能@GetMapping("/queryUserRole")public List

用Eolink进行测试