mybatisPLus 是mybatis的升级版，mybatis的功能都继承了都可以同样的使用

目录

Springboot + mybatisPLus_sql



MyBatisPlusConfig


package com.config;

import com.baomidou.mybatisplus.core.injector.ISqlInjector;
import com.baomidou.mybatisplus.extension.injector.LogicSqlInjector;
import com.baomidou.mybatisplus.extension.plugins.PaginationInterceptor;
import com.baomidou.mybatisplus.extension.plugins.PerformanceInterceptor;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Profile;

@Configuration
@MapperScan("com.mapper")
public class MyBatisPlusConfig {

    //分页插件
    @Bean
    public PaginationInterceptor paginationInterceptor() {
        return new PaginationInterceptor();
    }
    //逻辑删除插件
    @Bean
    public ISqlInjector sqlInjector() {
        return new LogicSqlInjector();
    }

//    sql执行效率插件
    @Bean
    @Profile({"dev","test"}) //设置dev、test环境开启
    public PerformanceInterceptor PerformanceInterceptor(){
        PerformanceInterceptor PerformanceInterceptor = new PerformanceInterceptor();
        PerformanceInterceptor.setMaxTime(1111);//设置sql执行的最大时间,如果超过了则不执行，抛异常
        PerformanceInterceptor.setFormat(true); //开启sql格式化
        return PerformanceInterceptor;
    }
}




UserMapper


package com.mapper;

import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.pojo.User;
import org.apache.ibatis.annotations.Select;
import org.springframework.stereotype.Repository;

import java.util.List;

@Repository
public interface UserMapper extends BaseMapper<User> {


    @Select("select * from user,user2  where user.id=user2.id")
    List<User> getUserById3();

    @Select("DELETE FROM User WHERE id = 3")
    List<User> getUserById2();

}




User
帅爷说如果使用联表查这里里面的字段就要自定义去加


package com.pojo;

import com.baomidou.mybatisplus.annotation.TableLogic;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

@Data
@AllArgsConstructor
@NoArgsConstructor
public class User {
    private int id;
    private String message;
    @TableLogic() //逻辑删除
    private Integer deleted;

}



MyBatisPlusApplication


package com;

import org.apache.ibatis.annotations.Mapper;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@MapperScan("com.mapper")
@SpringBootApplication
public class MyBatisPlusApplication {

    public static void main(String[] args) {
        SpringApplication.run(MyBatisPlusApplication.class, args);
    }

}



application.yml


### 应用名称
##spring.application.name=Mybatis_7_20
##下面这些内容是为了让MyBatis映射
##指定Mybatis的Mapper文件
#mybatis:
#  mapper-locations: classpath:/mapper/*xml
##指定Mybatis的实体目录
#  type-aliases-package: com.entity

spring:
  #设置开发环境
  profiles:
    active: dev
    ## 数据库驱动：
#    第一个数据库
  datasource:
      driver-class-name: com.mysql.cj.jdbc.Driver
  # 数据库连接地址
      url: jdbc:mysql://localhost:3306/datademo?serverTimezone=UTC
  # 数据库用户名&密码：
      username: root
      password: 669988

#配置日志
mybatis-plus:
  configuration:
    log-impl: org.apache.ibatis.logging.stdout.StdOutImpl

#逻辑删除
  global-config:
    db-config:
      logic-delete-value: 1 # 逻辑已删除值(默认为 1)
      logic-not-delete-value: 0 # 逻辑未删除值(默认为 0)

# 应用服务 WEB 访问端口
server:
  port: 8180



MyBatisPlusApplicationTests


package com;

import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.mapper.UserMapper;
import com.pojo.User;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;

import java.util.List;

@SpringBootTest
class MyBatisPlusApplicationTests {

    @Autowired
    private UserMapper  userMapper;


    @Test
//    查询所有
    void contextLoads() {
        List user = userMapper.getUserById3();
        user.forEach(System.out::println);
    }

    @Test
//    查询所有
    void contextLoads3() {
        List<User> user = userMapper.selectList(null);
        user.forEach(System.out::println);
    }
//
//    @Test
////    带id条件查询
//    void testselectid() {
//        User user = userMapper.selectById(1);
//        System.out.println(user);
//    }
//
//    @Test
////    in条件查询
//    void testselectidList() {
//        List<User> user = userMapper.selectBatchIds(Arrays.asList(1,2,3,4,5,6));
//        user.forEach(System.out::println);
//    }
//
//    @Test
////    按条件查询
//    public void testselectidBatchids() {
//        HashMap<String,Object> map=new HashMap<>();
//        map.put("id",2);
//        map.put("message","你好");
//        List<User> user =userMapper.selectByMap(map);
//        user.forEach(System.out::println);
//    }
//
//    // 插入
//    @Test
//    public void testInsert() {
//       User user=new User();
//       user.setMessage("kaibin666");
//       int result=userMapper.insert(user);
//       System.out.println(result); //受影响的行数
//       System.out.println(user);
//    }

//    // 更新
//    @Test
//    public void testUpdata() {
//        User user=new User();
////        user.setId(6);
//        user.setMessage("hahah");
//        int result=userMapper.updateById(user);
//        System.out.println(result); //受影响的行数
//        System.out.println(user);
//    }
//
    // 测试分页查询
    @Test
    public void testPage() {
//        参数一:第几页
//        参数二:每页条数
        Page<User> page=new Page<>(2,5);
//        查询所有
        userMapper.selectPage(page,null);
//        获取第2页的5条信息展示
        page.getRecords().forEach(System.out::println);
//        获取查询语句的总条数
        System.out.println(page.getTotal());
    }
//
//    //测试删除
//    @Test
//    public void testDeleteById(){
//        int result=userMapper.deleteById(4);
//        System.out.println(result); //受影响的行数
//    }
//
//    //测试id批量删除
//    @Test
//    public void testDeleteBatchId(){
//        int result=userMapper.deleteBatchIds(Arrays.asList(1,2,3));
//        System.out.println(result); //受影响的行数
//    }
//
//    //测试map条件删除
//    @Test
//    public void testDeleteMap(){
//        HashMap<String,Object> map=new HashMap<>();
//        map.put("message","你好");
//        List<User> result=userMapper.selectByMap(map);
//        System.out.println(result); //受影响的行数
//    }
//
}



WrapperTest


package com;

import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.mapper.UserMapper;
import com.pojo.User;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;

import java.util.List;

@SpringBootTest
public class WrapperTest {
    @Autowired
    private UserMapper userMapper;

//    @Test
//// 查询 message 和 id 不为空的 信息
//    void contextLoads() {
//        QueryWrapper<User> wrapper =new QueryWrapper<>();
//        wrapper
//                .isNotNull("message")
//                .isNotNull("id");
//        userMapper.selectList(wrapper).forEach(System.out::println);
//    }
//
    @Test
// 查询 message =张三的
    void contextLoads2() {
        QueryWrapper<User> wrapper =new QueryWrapper<>();
        wrapper
                .eq("message","kaibin");
        userMapper.selectList(wrapper).forEach(System.out::println);
        userMapper.selectCount(wrapper); //查询数据统计条数
    }
//
//     测试分页查询
// 测试分页查询
    @Test
    public void testPage() {
    //        参数一:第几页
    //        参数二:每页条数
        Page<User> page=new Page<>(2,5);
    //        查询所有
//        QueryWrapper<User> weapper=new QueryWrapper<>();
//    weapper.select("select id from user");
        userMapper.selectPage(page,null);
    //        获取第2页的5条信息展示
        page.getRecords().forEach(System.out::println);
    //        获取查询语句的总条数
        System.out.println(page.getTotal());
    }
//
    @Test
    public void test02() {
    QueryWrapper<User> weapper=new QueryWrapper<>();
//    weapper.inSql("id","select id from user");
    weapper.select("id");
    List<Object> objects=userMapper.selectObjs(weapper);
    objects.forEach(System.out::println);
    }
}


　　pom.xml


<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>com.example</groupId>
    <artifactId>MyBatis_Plus</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>MyBatis_Plus</name>
    <description>Demo project for Spring Boot</description>

    <properties>
        <java.version>1.8</java.version>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <spring-boot.version>2.3.7.RELEASE</spring-boot.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-jdbc</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-boot-starter</artifactId>
            <version>3.0.5</version>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
            <exclusions>
                <exclusion>
                    <groupId>org.junit.vintage</groupId>
                    <artifactId>junit-vintage-engine</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
    </dependencies>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-dependencies</artifactId>
                <version>${spring-boot.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.8.1</version>
                <configuration>
                    <source>1.8</source>
                    <target>1.8</target>
                    <encoding>UTF-8</encoding>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <version>2.3.7.RELEASE</version>
                <configuration>
                    <mainClass>com.MyBatisPlusApplication</mainClass>
                </configuration>
                <executions>
                    <execution>
                        <id>repackage</id>
                        <goals>
                            <goal>repackage</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>

</project>