SpringBoot整合Mybatis-Plus(SpringBoot3)

<?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>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>3.2.3</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com</groupId>
    <artifactId>demoPlus</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>demoPlus</name>
    <description>demoPlus</description>
    <properties>
        <java.version>17</java.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-thymeleaf</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>com.mysql</groupId>
            <artifactId>mysql-connector-j</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>

        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-boot-starter</artifactId>
            <version>3.5.5</version>
            <exclusions>
            <exclusion>
                <groupId>com.mybatis</groupId>
                <artifactId>mybatis-spring</artifactId>
            </exclusion>
            </exclusions>
        </dependency>


        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <scope>test</scope>
        </dependency>

        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
        </dependency>

        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis-spring</artifactId>
            <version>3.0.3</version>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

spring:
  datasource:
    url: jdbc:mysql://localhost:3306/自己数据库名字?useUnicode=true&characterEncoding=UTF-8&useSSL=false
    username: root
    password: 123456


mybatis-plus:
  configuration:
    log-impl: org.apache.ibatis.logging.stdout.StdOutImpl

package com.demoplus.pojo;

import com.baomidou.mybatisplus.annotation.TableName;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
import lombok.ToString;

@AllArgsConstructor
@NoArgsConstructor
@ToString
@Data
@TableName("t_user") //目标表名
public class User {
    private Long id;
    private String name;
    private Integer age;
    private String email;

}

package com.demoplus.mapper;

import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.demoplus.pojo.User;
import org.apache.ibatis.annotations.Mapper;

@Mapper
public interface UserMapper extends BaseMapper<User> {

}

package com.demoplus;

import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

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

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

}

package com.demoplus;

import com.demoplus.mapper.UserMapper;
import com.demoplus.pojo.User;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;

import javax.sql.DataSource;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.SQLException;
import java.sql.SQLFeatureNotSupportedException;
import java.sql.SQLOutput;
import java.util.*;
import java.util.logging.Logger;

@SpringBootTest
class DemoPlusApplicationTests {

    @Autowired
    private UserMapper userMapper;

    @Autowired
    private DataSource dataSource;

    @Test
    //检验数据库连接
    void  dataSource() throws SQLException{
        System.out.println(dataSource.getConnection());
    }



    // CREATE
    @Test
    //增加信息
    public void testInset(){
        User user = new User();
        user.setId(111L);
        user.setName("qqml");
        user.setAge(22);
        user.setEmail("4399@qq.com");
        int count = userMapper.insert(user);
        System.out.println((count == 1 ? "增加成功" : "增加失败"));
    }



    //delete
    @Test
    //通过id删除
    public void testDeleteById(){
        int count = userMapper.deleteById(163L);
        System.out.println((count == 1 ? "删除成功" : "删除失败"));
    }

    @Test
    //通过多个id批量删除
    public void testDeleteBatchIds(){
        List<Long> idList = Arrays.asList(178L, 211L);
        int count = userMapper.deleteBatchIds(idList);
        System.out.println((count == 1 ? "删除失败" : "删除成功"));
    }

    @Test
    // 通过条件删除
    public void testDeleteByMap(){
        Map<String, Object> map = new HashMap<>();
        map.put("email", "9292@qq.com");
        int count = userMapper.deleteByMap(map);
        System.out.println((count == 1 ? "删除成功" : "删除失败"));
    }



    //update
    @Test
    //根据id更新数据
    public void testUpdateById(){
        User user = new User(222L, "heige", 18, "2381@qq.com");
        int count = userMapper.updateById(user);
        System.out.println((count == 1 ? "更新成功" : "更新失败"));
    }



    //retrieve
    @Test
    //根据id查询用户信息
    public void testSelectById(){
        User user = userMapper.selectById(222L);
        System.out.println(user);
    }

    @Test
    //根据id列表查询数据
    public void testSelectBatchIds(){
        List<Long> idList = Arrays.asList(225L, 256L);
        List<User> userList = userMapper.selectBatchIds(idList);
        userList.forEach(System.out::println);
    }

    @Test
    //根据设置条件查询数据
    public void testSelectByMap(){
        Map<String, Object> map = new HashMap<>();
        map.put("age", 18);
        List<User> userList = userMapper.selectByMap(map);
        userList.forEach(System.out::println);
    }

    @Test
    //直接查询所有数据
    public void selectList(){
        List<User> user = userMapper.selectList(null);
        user.forEach(System.out::println);
    }

}