SpringBoot整合Mybatis-plus的具体使用

< dependencies >

     < dependency >

       < groupId >org.springframework.boot</ groupId >

       < artifactId >spring-boot-starter</ artifactId >

     </ dependency >

     <!--springboot程序测试依赖，如果是自动创建项目默认添加-->

     < dependency >

       < groupId >org.springframework.boot</ groupId >

       < artifactId >spring-boot-starter-test</ artifactId >

       < scope >test</ scope >

     </ dependency >

     < dependency >

       < groupId >org.projectlombok</ groupId >

       < artifactId >lombok</ artifactId >

       < version >1.16.10</ version >

       < scope >provided</ scope >

     </ dependency >

     <!-- 包含spirng Mvc ,tomcat的包包含requestMapping restController 等注解 -->

     < dependency >

       < groupId >org.springframework.boot</ groupId >

       < artifactId >spring-boot-starter-web</ artifactId >

     </ dependency >

     < dependency >

       < groupId >com.alibaba</ groupId >

       < artifactId >druid-spring-boot-starter</ artifactId >

       < version >1.1.10</ version >

     </ dependency >

     < dependency >

       < groupId >mysql</ groupId >

       < artifactId >mysql-connector-java</ artifactId >

     </ dependency >

     <!-- druid依赖 -->

     < dependency >

       < groupId >com.alibaba</ groupId >

       < artifactId >druid</ artifactId >

       < version >1.1.0</ version >

     </ dependency >

     <!-- mybatisPlus 核心库 -->

     < dependency >

       < groupId >com.baomidou</ groupId >

       < artifactId >mybatis-plus-boot-starter</ artifactId >

       < version >3.1.0</ version >

     </ dependency >

   </ dependencies >

server:

   port: 10100   #  配置启动端口号

mybatis:

   config-location: classpath:mybatis.cfg.xml    #  mybatis主配置文件所在路径

   type-aliases-package: com.demo.drools.entity  #  定义所有操作类的别名所在包

   mapper-locations:                                     #  所有的mapper映射文件

     - classpath:mapper/*.xml

spring: #springboot的配置

   datasource: #定义数据源

     #127.0.0.1为本机测试的ip，3306是mysql的端口号。serverTimezone是定义时区，照抄就好，mysql高版本需要定义这些东西

     #useSSL也是某些高版本mysql需要问有没有用SSL连接

     url: jdbc:mysql://127.0.0.1:3306/test?serverTimezone=GMT%2B8&useSSL=FALSE

     username: root  #数据库用户名，root为管理员

     password: 123456 #该数据库用户的密码

     # 使用druid数据源

     type: com.alibaba.druid.pool.DruidDataSource

# mybatis-plus相关配置

mybatis-plus:

   # xml扫描，多个目录用逗号或者分号分隔（告诉 Mapper 所对应的 XML 文件位置）

   mapper-locations: classpath:mapper/*.xml

   # 以下配置均有默认值,可以不设置

   global-config:

     db-config:

       #主键类型 AUTO:"数据库ID自增" INPUT:"用户输入ID",ID_WORKER:"全局唯一ID (数字类型唯一ID)", UUID:"全局唯一ID UUID";

       id-type: auto

       #字段策略 IGNORED:"忽略判断"  NOT_NULL:"非 NULL 判断")  NOT_EMPTY:"非空判断"

       field-strategy: NOT_EMPTY

       #数据库类型

       db-type: MYSQL

   configuration:

     # 是否开启自动驼峰命名规则映射:从数据库列名到Java属性驼峰命名的类似映射

     map-underscore-to-camel-case: true

     # 如果查询结果中包含空值的列，则 MyBatis 在映射的时候，不会映射这个字段

     call-setters-on-nulls: true

     # 这个配置会将执行的sql打印出来，在开发或测试的时候可以用

     log-impl: org.apache.ibatis.logging.stdout.StdOutImpl

package com.demo.drools.entity;

import com.baomidou.mybatisplus.annotation.IdType;

import com.baomidou.mybatisplus.annotation.TableId;

import com.baomidou.mybatisplus.annotation.TableName;

import lombok.Data;

/**

  * TODO your comment

  *

  * @author Yujiaqi

  * @date 2020/12/2 19:14

  */

@Data

@TableName ( "user_info" ) //@TableName中的值对应着表名

public class UserInfoEntity {

     /**

      * 主键

      * @TableId中可以决定主键的类型,不写会采取默认值,默认值可以在yml中配置

      * AUTO: 数据库ID自增

      * INPUT: 用户输入ID

      * ID_WORKER: 全局唯一ID，Long类型的主键

      * ID_WORKER_STR: 字符串全局唯一ID

      * UUID: 全局唯一ID，UUID类型的主键

      * NONE: 该类型为未设置主键类型

      */

     @TableId (type = IdType.AUTO)

     private Long id;

     /**

      * 姓名

      */

     private String name;

     /**

      * 年龄

      */

     private Integer age;

     /**

      * 技能

      */

     private String skill;

     /**

      * 评价

      */

     private String evaluate;

     /**

      * 分数

      */

     private Long fraction;

}

package com.demo.drools.config;

import com.baomidou.mybatisplus.extension.plugins.PaginationInterceptor;

import com.baomidou.mybatisplus.extension.plugins.PerformanceInterceptor;

import org.springframework.context.annotation.Bean;

/**

  * TODO your comment

  *

  * @author Yujiaqi

  * @date 2020/12/2 19:14

  */

public class MybatisPlusConfig {

     /**

      * mybatis-plus SQL执行效率插件【生产环境可以关闭】

      */

     @Bean

     public PerformanceInterceptor performanceInterceptor() {

         return new PerformanceInterceptor();

     }

     /**

      * 分页插件

      */

     @Bean

     public PaginationInterceptor paginationInterceptor() {

         return new PaginationInterceptor();

     }

}

package com.demo.drools;

import org.mybatis.spring.annotation.MapperScan;

import org.springframework.boot.SpringApplication;

import org.springframework.boot.autoconfigure.SpringBootApplication;

/**

  * @author 于嘉琪

  */

@SpringBootApplication

//@MapperScan和dao层添加@Mapper注解意思一样

@MapperScan (basePackages = "com.demo.drools.dao" )

public class DroolsApplication {

     public static void main(String[] args) {

         SpringApplication.run(DroolsApplication. class , args);

     }

}

package com.demo.drools.dao;

import com.baomidou.mybatisplus.core.mapper.BaseMapper;

import com.baomidou.mybatisplus.core.metadata.IPage;

import com.demo.drools.entity.UserInfoEntity;

import org.apache.ibatis.annotations.Mapper;

import org.apache.ibatis.annotations.Param;

/**

  * 用户信息DAO

  *

  * @author Yujiaqi

  * @date 2020/12/2 19:16

  */

@Mapper

public interface UserInfoDao extends BaseMapper<UserInfoEntity> {

}

package com.demo.drools.service;

import com.baomidou.mybatisplus.core.metadata.IPage;

import com.baomidou.mybatisplus.extension.service.IService;

import com.demo.drools.entity.UserInfoEntity;

/**

  * TODO your comment

  *

  * @author Yujiaqi

  * @date 2020/12/2 19:17

  */

public interface UserInfoService extends IService<UserInfoEntity> {

}

package com.demo.drools.service.impl;

import com.baomidou.mybatisplus.core.metadata.IPage;

import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;

import com.demo.drools.dao.UserInfoDao;

import com.demo.drools.entity.UserInfoEntity;

import com.demo.drools.service.UserInfoService;

import org.springframework.stereotype.Service;

import javax.annotation.Resource;

/**

  * TODO your comment

  *

  * @author Yujiaqi

  * @date 2020/12/2 19:18

  */

@Service

public class UserInfoSerivceImpl extends ServiceImpl<UserInfoDao, UserInfoEntity> implements UserInfoService {

}

package com.demo.drools.controller;

import com.baomidou.mybatisplus.core.metadata.IPage;

import com.baomidou.mybatisplus.extension.plugins.pagination.Page;

import com.demo.drools.entity.UserInfoEntity;

import com.demo.drools.service.UserInfoService;

import org.springframework.beans.factory.annotation.Autowired;

import org.springframework.web.bind.annotation.RequestMapping;

import org.springframework.web.bind.annotation.RestController;

import java.util.ArrayList;

import java.util.Collection;

import java.util.HashMap;

import java.util.List;

import java.util.Map;

/**

  * TODO your comment

  *

  * @author Yujiaqi

  * @date 2020/12/2 19:20

  */

@RestController

@RequestMapping ( "/userInfo" )

public class UserInfoController {

     @Autowired

     private UserInfoService userInfoService;

     /**

      * 根据ID获取用户信息

      * @Author Sans

      * @CreateTime 2019/6/8 16:34

      * @Param  userId  用户ID

      * @Return UserInfoEntity 用户实体

      */

     @RequestMapping ( "/getInfo" )

     public UserInfoEntity getInfo(String userId){

         UserInfoEntity userInfoEntity = userInfoService.getById(userId);

         return userInfoEntity;

     }

     /**

      * 查询全部信息

      * @Author Sans

      * @CreateTime 2019/6/8 16:35

      * @Param  userId  用户ID

      * @Return List<UserInfoEntity> 用户实体集合

      */

     @RequestMapping ( "/getList" )

     public List<UserInfoEntity> getList(){

         List<UserInfoEntity> userInfoEntityList = userInfoService.list();

         return userInfoEntityList;

     }

     /**

      * 分页查询全部数据

      * @Author Sans

      * @CreateTime 2019/6/8 16:37

      * @Return IPage<UserInfoEntity> 分页数据

      */

     @RequestMapping ( "/getInfoListPage" )

     public IPage<UserInfoEntity> getInfoListPage(){

         //需要在Config配置类中配置分页插件

         IPage<UserInfoEntity> page = new Page<>();

         page.setCurrent( 5 ); //当前页

         page.setSize( 1 );    //每页条数

         page = userInfoService.page(page);

         return page;

     }

     /**

      * 根据指定字段查询用户信息集合

      * @Author Sans

      * @CreateTime 2019/6/8 16:39

      * @Return Collection<UserInfoEntity> 用户实体集合

      */

     @RequestMapping ( "/getListMap" )

     public Collection<UserInfoEntity> getListMap(){

         Map<String,Object> map = new HashMap<>();

         //kay是字段名 value是字段值

         map.put( "age" , 20 );

         Collection<UserInfoEntity> userInfoEntityList = userInfoService.listByMap(map);

         return userInfoEntityList;

     }

     /**

      * 新增用户信息

      * @Author Sans

      * @CreateTime 2019/6/8 16:40

      */

     @RequestMapping ( "/saveInfo" )

     public void saveInfo(){

         UserInfoEntity userInfoEntity = new UserInfoEntity();

         userInfoEntity.setName( "小龙" );

         userInfoEntity.setSkill( "JAVA" );

         userInfoEntity.setAge( 18 );

         userInfoEntity.setFraction(59L);

         userInfoEntity.setEvaluate( "该学生是一个在改BUG的码农" );

         userInfoService.save(userInfoEntity);

     }

     /**

      * 批量新增用户信息

      * @Author Sans

      * @CreateTime 2019/6/8 16:42

      */

     @RequestMapping ( "/saveInfoList" )

     public void saveInfoList(){

         //创建对象

         UserInfoEntity sans = new UserInfoEntity();

         sans.setName( "Sans" );

         sans.setSkill( "睡觉" );

         sans.setAge( 18 );

         sans.setFraction(60L);

         sans.setEvaluate( "Sans是一个爱睡觉,并且身材较矮骨骼巨大的骷髅小胖子" );

         UserInfoEntity papyrus = new UserInfoEntity();

         papyrus.setName( "papyrus" );

         papyrus.setSkill( "JAVA" );

         papyrus.setAge( 18 );

         papyrus.setFraction(58L);

         papyrus.setEvaluate( "Papyrus是一个讲话大声、个性张扬的骷髅，给人自信、有魅力的骷髅小瘦子" );

         //批量保存

         List<UserInfoEntity> list = new ArrayList<>();

         list.add(sans);

         list.add(papyrus);

         userInfoService.saveBatch(list);

     }

     /**

      * 更新用户信息

      * @Author Sans

      * @CreateTime 2019/6/8 16:47

      */

     @RequestMapping ( "/updateInfo" )

     public void updateInfo(){

         //根据实体中的ID去更新,其他字段如果值为null则不会更新该字段,参考yml配置文件

         UserInfoEntity userInfoEntity = new UserInfoEntity();

         userInfoEntity.setId(1L);

         userInfoEntity.setAge( 19 );

         userInfoService.updateById(userInfoEntity);

     }

     /**

      * 新增或者更新用户信息

      * @Author Sans

      * @CreateTime 2019/6/8 16:50

      */

     @RequestMapping ( "/saveOrUpdateInfo" )

     public void saveOrUpdate(){

         //传入的实体类userInfoEntity中ID为null就会新增(ID自增)

         //实体类ID值存在,如果数据库存在ID就会更新,如果不存在就会新增

         UserInfoEntity userInfoEntity = new UserInfoEntity();

         userInfoEntity.setId(1L);

         userInfoEntity.setAge( 20 );

         userInfoService.saveOrUpdate(userInfoEntity);

     }

     /**

      * 根据ID删除用户信息

      * @Author Sans

      * @CreateTime 2019/6/8 16:52

      */

     @RequestMapping ( "/deleteInfo" )

     public void deleteInfo(String userId){

         userInfoService.removeById(userId);

     }

     /**

      * 根据ID批量删除用户信息

      * @Author Sans

      * @CreateTime 2019/6/8 16:55

      */

     @RequestMapping ( "/deleteInfoList" )

     public void deleteInfoList(){

         List<String> userIdlist = new ArrayList<>();

         userIdlist.add( "12" );

         userIdlist.add( "13" );

         userInfoService.removeByIds(userIdlist);

     }

     /**

      * 根据指定字段删除用户信息

      * @Author Sans

      * @CreateTime 2019/6/8 16:57

      */

     @RequestMapping ( "/deleteInfoMap" )

     public void deleteInfoMap(){

         //kay是字段名 value是字段值

         Map<String,Object> map = new HashMap<>();

         map.put( "skill" , "删除" );

         map.put( "fraction" ,10L);

         userInfoService.removeByMap(map);

     }

}

package com.demo.drools.controller;

import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;

import com.baomidou.mybatisplus.core.metadata.IPage;

import com.baomidou.mybatisplus.extension.plugins.pagination.Page;

import com.demo.drools.entity.UserInfoEntity;

import com.demo.drools.service.UserInfoService;

import org.springframework.beans.factory.annotation.Autowired;

import org.springframework.web.bind.annotation.RequestMapping;

import java.util.HashMap;

import java.util.List;

import java.util.Map;

/**

  * TODO your comment

  *

  * @author Yujiaqi

  * @date 2020/12/2 19:28

  */

public class UserInfoPlusController {

     @Autowired

     private UserInfoService userInfoService;

     /**

      * MP扩展演示

      * @Author Sans

      * @CreateTime 2019/6/8 16:37

      * @Return Map<String,Object> 返回数据

      */

     @RequestMapping ( "/getInfoListPlus" )

     public Map<String,Object> getInfoListPage(){

         //初始化返回类

         Map<String,Object> result = new HashMap<>();

         //查询年龄等于18岁的学生

         //等价SQL: SELECT id,name,age,skill,evaluate,fraction FROM user_info WHERE age = 18

         QueryWrapper<UserInfoEntity> queryWrapper1 = new QueryWrapper<>();

         queryWrapper1.lambda().eq(UserInfoEntity::getAge, 18 );

         List<UserInfoEntity> userInfoEntityList1 = userInfoService.list(queryWrapper1);

         result.put( "studentAge18" ,userInfoEntityList1);

         //查询年龄大于5岁的学生且小于等于18岁的学生

         //等价SQL: SELECT id,name,age,skill,evaluate,fraction FROM user_info WHERE age > 5 AND age <= 18

         QueryWrapper<UserInfoEntity> queryWrapper2 = new QueryWrapper<>();

         queryWrapper2.lambda().gt(UserInfoEntity::getAge, 5 );

         queryWrapper2.lambda().le(UserInfoEntity::getAge, 18 );

         List<UserInfoEntity> userInfoEntityList2 = userInfoService.list(queryWrapper2);

         result.put( "studentAge5" ,userInfoEntityList2);

         //模糊查询技能字段带有"画"的数据,并按照年龄降序

         //等价SQL: SELECT id,name,age,skill,evaluate,fraction FROM user_info WHERE skill LIKE '%画%' ORDER BY age DESC

         QueryWrapper<UserInfoEntity> queryWrapper3 = new QueryWrapper<>();

         queryWrapper3.lambda().like(UserInfoEntity::getSkill, "画" );

         queryWrapper3.lambda().orderByDesc(UserInfoEntity::getAge);

         List<UserInfoEntity> userInfoEntityList3 = userInfoService.list(queryWrapper3);

         result.put( "studentAgeSkill" ,userInfoEntityList3);

         //模糊查询名字带有"小"或者年龄大于18的学生

         //等价SQL: SELECT id,name,age,skill,evaluate,fraction FROM user_info WHERE name LIKE '%小%' OR age > 18

         QueryWrapper<UserInfoEntity> queryWrapper4 = new QueryWrapper<>();

         queryWrapper4.lambda().like(UserInfoEntity::getName, "小" );

         queryWrapper4.lambda().or().gt(UserInfoEntity::getAge, 18 );

         List<UserInfoEntity> userInfoEntityList4 = userInfoService.list(queryWrapper4);

         result.put( "studentOr" ,userInfoEntityList4);

         //查询评价不为null的学生,并且分页

         //等价SQL: SELECT id,name,age,skill,evaluate,fraction FROM user_info WHERE evaluate IS NOT NULL LIMIT 0,5

         IPage<UserInfoEntity> page = new Page<>();

         page.setCurrent( 1 );

         page.setSize( 5 );

         QueryWrapper<UserInfoEntity> queryWrapper5 = new QueryWrapper<>();

         queryWrapper5.lambda().isNotNull(UserInfoEntity::getEvaluate);

         page = userInfoService.page(page,queryWrapper5);

         result.put( "studentPage" ,page);

         return result;

     }

}

/**

      * 查询大于该分数的学生

      * @Author Sans

      * @CreateTime 2019/6/9 14:28

      * @Param  page  分页参数

      * @Param  fraction  分数

      * @Return IPage<UserInfoEntity> 分页数据

      */

     IPage<UserInfoEntity> selectUserInfoByGtFraction(

             @Param (value = "page" ) IPage<UserInfoEntity> page,

             @Param (value = "fraction" )Long fraction);

/**

      * 查询大于该分数的学生

      * @Author Sans

      * @CreateTime 2019/6/9 14:27

      * @Param  page  分页参数

      * @Param  fraction  分数

      * @Return IPage<UserInfoEntity> 分页数据

      */

     IPage<UserInfoEntity> selectUserInfoByGtFraction(IPage<UserInfoEntity> page,Long fraction);

/**

      * 查询大于该分数的学生

      * @Author Sans

      * @CreateTime 2019/6/9 14:27

      * @Param  page  分页参数

      * @Param  fraction  分数

      * @Return IPage<UserInfoEntity> 分页数据

      */

     IPage<UserInfoEntity> selectUserInfoByGtFraction(IPage<UserInfoEntity> page,Long fraction);

/**

     * MP自定义SQL

     * @Author Sans

     * @CreateTime 2019/6/9 14:37

     * @Return IPage<UserInfoEntity> 分页数据

     */

    @RequestMapping ( "/getInfoListSQL" )

    public IPage<UserInfoEntity> getInfoListSQL(){

        //查询大于60分以上的学生,并且分页

        IPage<UserInfoEntity> page = new Page<>();

        page.setCurrent( 1 );

        page.setSize( 5 );

        page = userInfoService.selectUserInfoByGtFraction(page,60L);

        return page;

    }

<? 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.demo.drools.dao.UserInfoDao" >

   <!-- Sans 2019/6/9 14:35 -->

   < select id = "selectUserInfoByGtFraction" resultType = "com.demo.drools.entity.UserInfoEntity" >

     SELECT * FROM user_info WHERE fraction > #{fraction}

     </ select >

</ mapper >