Mybatis-plus 入门案例 通用Mapper

 <!--确定spring boot的版本-->
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.3.5.RELEASE</version>
    </parent>   
<dependencies>
        <!-- web 开发 -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <!--MySQL数据库驱动-->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>
        <!--支持lombok-->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
        </dependency>
        <!--测试-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
        </dependency>
        <!-- https://mvnrepository.com/artifact/com.baomidou/mybatis-plus-boot-starter -->
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-boot-starter</artifactId>
            <version>3.4.0</version>
        </dependency>
    </dependencies>

spring:
  datasource:
    driver-class-name: com.mysql.cj.jdbc.Driver
    url: jdbc:mysql://localhost:3306/cloud_db1?useUnicode=true&characterEncoding=UTF-8&serverTimezone=UTC
    username: root
    password: root
mybatis-plus:
  configuration:
    log-impl: org.apache.ibatis.logging.stdout.StdOutImpl  #输出日志
    map-underscore-to-camel-case: true  #驼峰命名
  global-config:
    db-config:
      table-prefix: tmp_ #表名前缀
  type-aliases-package: com.czxy.domain #别名包扫描路径
  mapper-locations: classpath*:/mapper/**/*.xml #映射文件位置

数据库和表

CREATE DATABASE cloud_db1;
USE cloud_db1;
CREATE TABLE `tmp_customer` (
  `cid` INT(11) NOT NULL AUTO_INCREMENT,
  `cname` VARCHAR(50) DEFAULT NULL,
  `password` VARCHAR(32) DEFAULT NULL,
  `telephone` VARCHAR(11) DEFAULT NULL,
  `money` DOUBLE DEFAULT NULL,
  `version` INT(11) DEFAULT NULL,
  `create_time` DATE DEFAULT NULL,
  `update_time` DATE DEFAULT NULL,
  PRIMARY KEY (`cid`)
);

INSERT  INTO `tmp_customer`(`cid`,`cname`,`password`,`telephone`,`money`,`version`,`create_time`,`update_time`) 
VALUES (1,'jack','1234','110',1000,NULL,NULL,NULL),(2,'rose','1234','112',1000,NULL,NULL,NULL),(3,'tom','1234','119',1000,NULL,NULL,NULL);

配置JavaBean

• @TableName 表名注解，value属性设置表名

package com.czxy.domain;

import com.baomidou.mybatisplus.annotation.IdType;
import com.baomidou.mybatisplus.annotation.TableField;
import com.baomidou.mybatisplus.annotation.TableId;
import com.baomidou.mybatisplus.annotation.TableName;
import lombok.Data;

import java.util.List;


@Data
@TableName("tmp_customer")
public class Customer {
    @TableId(type = IdType.AUTO)
    private Integer cid;
    private String cname;
    private String password;
    private String telephone;
    private String money;

    private Integer version;

    @TableField(exist = false)
    private List<Integer> ids;
}

编写dao

package com.czxy.mapper;

import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.czxy.mp.domain.Customer;
import org.apache.ibatis.annotations.Mapper;

@Mapper
public interface CustomerMapper extends BaseMapper<Customer> {
}

编写启动类

package com.czxy;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

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

编写测试类

package com.czxy;

import com.czxy.mp.MybatisPlusApplication;
import com.czxy.mp.domain.Customer;
import com.czxy.mp.mapper.CustomerMapper;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;

import javax.annotation.Resource;
import java.util.List;

 
@RunWith(SpringRunner.class)
@SpringBootTest(classes = MybatisPlusApplication.class)
public class TestDemo01 {
    @Resource
    private CustomerMapper customerMapper;


    // 查询所有
    @Test
    public void testFindAll() {
        List<Customer> list = customerMapper.selectList(null);
        list.forEach(System.out::println);
    }


    @Test // Map条件查询
    public void testMap(){

        Map map = new HashMap();
        //map.put("cname","rose");
        map.put("password","1234");

        List list = customerMapper.selectByMap(map);
        list.forEach(System.out::println);

    }

    @Test    // 添加
    public void testInsert(){

        Customer customer = new Customer();
        // 设置什么加什么
        customer.setCname("测试");

        customerMapper.insert(customer);
        System.out.println(customer);

    }


    @Test //更新
    public void testUpdate(){

        Customer customer = new Customer();
        customer.setCid(4);
        customer.setCname("测试666");
        customer.setPassword("666");
        customer.setMoney(1000d);
        customer.setTelephone("111");

        // 需要给 Customer 设置 @TableId
        customerMapper.updateById(customer);
        // 更新所有用户信息
        //customerMapper.update(customer,null);
        System.out.println(customer);

    }

    @Test  //删除
    public  void testDelete(){

        // 需要给 Customer设置 @TableId
        int i = customerMapper.deleteById(4);
        // 批量删除
        //int i = customerMapper.deleteBatchIds(Arrays.asList(2,3));
        System.out.println(i);

    }


}