目录
4.Mybatisplus中使用Mybatis实现多表联查功能
新建一个springboot项目,注意:要勾选择相关的数据库


解决上述的方案:就是降低版本

导入pom依赖:
mysql
mysql-connector-java
5.1.44

application.yml:
- mybatis:
- mapper-locations: classpath:mappers/*xml
- type-aliases-package: com.xbb.springboot02mybatis.mybatis.entity
- server:
- port: 8080
- spring:
- application:
- name: springboot02mybatis
- datasource:
- driver-class-name: com.mysql.jdbc.Driver
- name: defaultDataSource
- password: 123456
- url: jdbc:mysql://localhost:3306/mybatis_ssm?useUnicode=true&characterEncoding=UTF-8
- username: 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 改三个地方,类名要跟创建的类名保持一致,还有上面那个yml里面的mappers后加上/**,还要改对生成的位置在我创建的resource里面的mappers生成在这里面才可以
"http://mybatis.org/dtd/mybatis-generator-config_1_0.dtd" >
connectionURL="${jdbc.url}" userId="${jdbc.username}" password="${jdbc.password}"/>
targetProject="src/main/java">
targetProject="src/main/resources/mappers">
targetProject="src/main/java" type="XMLMAPPER">
"t_mvc_book" domainObjectName="Book"
enableCountByExample="false" enableDeleteByExample="false"
enableSelectByExample="false" enableUpdateByExample="false">
pom.xml:
复制代码生成的插件
org.mybatis.generator
mybatis-generator-maven-plugin
1.3.2
mysql
mysql-connector-java
5.1.44
true
利用Eolink进行测试,这里我就创建一个类来测试 BookController.java
- @RestController
- @RequestMapping("/mybatis")
- public class BookController {
- @Autowired
- private BookMapper bookMapper;
-
- // 查询
- @GetMapping("/get")
- public Book get(Integer bid){
- return bookMapper.selectByPrimaryKey(bid);
- }
-
- // 删除
- @DeleteMapping("/delete")
- public int delete(Integer bid){
- return bookMapper.deleteByPrimaryKey(bid);
- }
-
- // 新增
- @PutMapping("/add")
- public int add(Book book){
- return bookMapper.insertSelective(book);
- }
-
- }
放到测试软件上进行测试即可:

学习网址:
https://baomidou.com/
https://baomidou.com/有兴趣的可以进去了解
新建一个springboot项目:

在pom依赖中添加相关配置:
com.baomidou
mybatis-plus-boot-starter
3.4.2
com.baomidou
mybatis-plus-generator
3.4.1
org.freemarker
freemarker
2.3.31
把application.properties转换成yml文件方便查看
进入网址查找代码
代码生成Mybatis-plus:
- package com.xbb.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();
- String projectPath = System.getProperty("user.dir") + "/testspboot03";
- System.out.println(projectPath);
-
- gc.setOutputDir(projectPath + "/src/main/java");
- gc.setOpen(false);
- gc.setBaseResultMap(true);//生成BaseResultMap
- gc.setActiveRecord(false);// 不需要ActiveRecord特性的请改为false
- gc.setEnableCache(false);// XML 二级缓存
- gc.setBaseResultMap(true);// XML ResultMap
- gc.setBaseColumnList(true);// XML columList
- //gc.setSwagger2(true); //实体属性 Swagger2 注解
- gc.setAuthor("lky");
-
- // 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);
- }
- pc.setParent("com.zking.demo")
- .setMapper("mapper")
- .setService("service")
- .setController("controller")
- .setEntity("model");
- mpg.setPackageInfo(pc);
-
- // 4.自定义配置
- InjectionConfig cfg = new InjectionConfig() {
- @Override
- public void initMap() {
- // to do nothing
- }
- };
-
- // 如果模板引擎是 freemarker
- String 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) {
- @Override
- public 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plus
- strategy.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_user
- strategy.setTablePrefix("t_", "t_sys_");
- //strategy.setTablePrefix(scanner("请输入表前缀"));
- mpg.setStrategy(strategy);
- mpg.setTemplateEngine(new FreemarkerTemplateEngine());
- // 执行
- mpg.execute();
- }
- }
MPGenerator.java :
- package com.xbb.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,就是它test02
- String projectPath = System.getProperty("user.dir") + "/springbootmp";
- System.out.println(projectPath);
-
- gc.setOutputDir(projectPath + "/src/main/java");
- gc.setOpen(false);
- gc.setBaseResultMap(true);//生成BaseResultMap
- gc.setActiveRecord(false);// 不需要ActiveRecord特性的请改为false
- gc.setEnableCache(false);// XML 二级缓存
- gc.setBaseResultMap(true);// XML ResultMap
- gc.setBaseColumnList(true);// XML columList
- //gc.setSwagger2(true); //实体属性 Swagger2 注解
- gc.setAuthor("jwj");
-
- // 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.zking.springbootmp")
- .setMapper("mapper")
- .setService("service")
- .setController("controller")
- .setEntity("model");
- mpg.setPackageInfo(pc);
-
- // 4.自定义配置
- InjectionConfig cfg = new InjectionConfig() {
- @Override
- public void initMap() {
- // to do nothing
- }
- };
-
- // 如果模板引擎是 freemarker
- String 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) {
- @Override
- public 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plus
- strategy.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_user
- strategy.setTablePrefix("t_", "t_sys_");
- //strategy.setTablePrefix(scanner("请输入表前缀"));
- mpg.setStrategy(strategy);
- mpg.setTemplateEngine(new FreemarkerTemplateEngine());
- // 执行
- mpg.execute();
- }
- }
代码生成完成我们要相关以下四个点:
1.目前我们的项目是springbootmp 这是代码生成的根路径,这就是配置地址
2.作者
3.数据库的地址、密码和用户名换成自己的
4.指的是我目前项目的启动类所在的位置,就是SpringbootmpApplication它的上一方目录
生成全部代码展示:
MvcBookMapper.xml:
- "1.0" encoding="UTF-8"?>
- "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
"com.zking.springbootmp.book.mapper.MvcBookMapper"> -
-
-
"BaseResultMap" type="com.zking.springbootmp.book.model.MvcBook"> -
"bid" property="bid" /> -
"bname" property="bname" /> -
"price" property="price" /> -
-
-
-
"Base_Column_List"> - bid, bname, price
-
-
MvcBookMapper.java:
- package com.zking.springbootmp.book.mapper;
-
- import com.zking.springbootmp.book.model.MvcBook;
- import com.baomidou.mybatisplus.core.mapper.BaseMapper;
- import org.springframework.stereotype.Repository;
-
- /**
- * @author冰冰
- * @create 2022-11-05 10:31
- */
- @Repository
- public interface MvcBookMapper extends BaseMapper
{ -
- }
MvcBookServiceImpl.java:
- package com.zking.springbootmp.book.service.impl;
-
- import com.zking.springbootmp.book.model.MvcBook;
- import com.zking.springbootmp.book.mapper.MvcBookMapper;
- import com.zking.springbootmp.book.service.MvcBookService;
- import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
- import org.springframework.stereotype.Service;
-
-
- @Service
- public class MvcBookServiceImpl extends ServiceImpl
implements MvcBookService { -
- }
SpringbootmpApplication.java:
- package com.xbb.springbootmp;
-
- import org.mybatis.spring.annotation.MapperScan;
- import org.springframework.boot.SpringApplication;
- import org.springframework.boot.autoconfigure.SpringBootApplication;
- import org.springframework.transaction.annotation.EnableTransactionManagement;
-
- @MapperScan("com.zking.springbootmp.book.mapper")
- @EnableTransactionManagement
- @SpringBootApplication
- public class SpringbootmpApplication {
-
- public static void main(String[] args) {
- SpringApplication.run(SpringbootmpApplication.class, args);
- }
-
- }
在MvcBookMapper.xml中写入代码如下:
在MvcBookService.java:
List
在MvcBookServiceImpl.java:
@Autowired private MvcBookMapper bookMapper; @Override public List
在MvcBookController.java中加入代码如下:
// 多表联查,用户账户对应角色的功能,论证mybatisplus是一样可以使用mybatis功能
@GetMapping("/querUserRole")
public List
最后在测试软件里面进行测试即可!!!