MyBatis-Plus 和达梦数据库实现高效数据持久化

一、添加依赖

首先，我们需要在项目的 pom.xml 文件中添加 MyBatis-Plus 和达梦数据库的依赖：

    <dependencies><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</artifactId></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-test</artifactId><scope>test</scope></dependency><!--  添加dm8 jdbc jar 包依赖--><dependency><groupId>com.dm</groupId><artifactId>DmJdbcDriver</artifactId><version>1.8.0</version></dependency><dependency><groupId>com.baomidou</groupId><artifactId>mybatis-plus-boot-starter</artifactId><version>3.5.2</version></dependency><dependency><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId></dependency></dependencies>

二、配置数据源

在 Spring Boot 的配置文件 application.properties 或 application.yml 中配置达梦数据库的连接信息：

spring:datasource:url: jdbc:dm://localhost:5236username: 账号password: 密码driver-class-name: dm.jdbc.driver.DmDriver

之后可以使用MyBatisX生成以下代码

三、创建实体类和 Mapper 接口

创建与数据库表对应的实体类，并使用 MyBatis-Plus 注解标注主键和表名等信息：

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 java.io.Serializable;import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;/*** @TableName student*/
@TableName(value = "lps.student")
@Data
@AllArgsConstructor
@NoArgsConstructor
public class Student implements Serializable {/*** */@TableIdprivate String id;/*** */private String name;/*** */private Integer age;}

接着，创建继承自 BaseMapper 的 Mapper 接口：

import com.lps.domain.Student;
import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import org.apache.ibatis.annotations.Mapper;/**
* @author 19449
* @description 针对表【student】的数据库操作Mapper
* @createDate 2023-08-01 16:10:31
* @Entity com.lps.domain.Student
*/
@Mapper
public interface StudentMapper extends BaseMapper<Student> {}

完成mapper.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapperPUBLIC "-//mybatis.org//DTD Mapper 3.0//EN""http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.lps.mapper.StudentMapper"><resultMap id="BaseResultMap" type="com.lps.domain.Student"><id property="id" column="id" jdbcType="VARCHAR"/><result property="name" column="name" jdbcType="VARCHAR"/><result property="age" column="age" jdbcType="OTHER"/></resultMap><sql id="Base_Column_List">id,name,age</sql>
</mapper>

四、创建 Service 层

创建 Service 接口和实现类，继承自 IService 和 ServiceImpl：

import com.lps.domain.Student;
import com.baomidou.mybatisplus.extension.service.IService;import java.util.List;/*** @author 19449* @description 针对表【student】的数据库操作Service* @createDate 2023-08-01 16:10:31*/
public interface StudentService extends IService<Student> {List<Student> selectAll();void insert(Student student);void deleteBatch(List<Student> studentList);void deleteAll();}

service实现类

import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.lps.domain.Student;
import com.lps.service.StudentService;
import com.lps.mapper.StudentMapper;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;import java.util.List;
import java.util.stream.Collectors;/*** @author 19449* @description 针对表【student】的数据库操作Service实现* @createDate 2023-08-01 16:10:31*/
@Service
public class StudentServiceImpl extends ServiceImpl<StudentMapper, Student>implements StudentService {@Autowiredprivate StudentMapper studentMapper;@Overridepublic List<Student> selectAll() {return studentMapper.selectList(null);}@Overridepublic void insert(Student student) {studentMapper.insert(student);}@Overridepublic void deleteBatch(List<Student> studentList) {studentMapper.deleteBatchIds(studentList.stream().map(students -> students.getId()).collect(Collectors.toList()));}@Overridepublic void deleteAll() {studentMapper.delete(null);}}

五、进行 CRUD 操作

现在就可以在业务逻辑中使用 YourService 进行增删改查操作了：

package com.lps;import com.lps.domain.Student;
import com.lps.service.StudentService;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;import java.util.ArrayList;
import java.util.List;@SpringBootTest
class SpringBootDm7ApplicationTests {@AutowiredStudentService studentService;/*** 查询所有*/@Testvoid contextLoadSelectAll() {List<Student> students = studentService.selectAll();for (Student student : students) {System.out.println(student);}}/*** 单条插入*/@Testvoid contextLoadsInsert() {Student student = new Student("666","刘品水",18);studentService.insert(student);}/*** 循环里做插入 主打就是挨训*/@Testvoid contextLoadsInsert2() {//还有优化空间 下篇博客见List<Student> studentList=new ArrayList<>();for (int i = 1; i <= 100000; i++) {Student student1 = new Student(i+"","刘品水"+i,1+i);studentList.add(student1);}System.out.println(studentList.size());long beginTime = System.currentTimeMillis();for (Student student : studentList) {studentService.insert(student);}long endTime = System.currentTimeMillis();long spendTime = endTime - beginTime;System.out.println("用时："+spendTime+"毫秒");}/*** 批量插入*/@Testvoid contextLoadsSaveBatch() {//还有优化空间 下篇博客见List<Student> studentList=new ArrayList<>();for (int i = 1; i <= 1000000; i++) {Student student1 = new Student(i+"","刘品水"+i,1+i);studentList.add(student1);}System.out.println(studentList.size());long beginTime = System.currentTimeMillis();studentService.saveBatch(studentList,1000000);long endTime = System.currentTimeMillis();long spendTime = endTime - beginTime;System.out.println("用时："+spendTime+"毫秒");}/*** 批量保存或者批量更新*/@Testvoid contextLoadSaveOrUpdateBatch() {List<Student> studentList=new ArrayList<>();Student student1 = new Student("668","吴彦祖",18);Student student2 = new Student("669","彭于晏",18);Student student3 = new Student("670","霍建华",18);studentList.add(student1);studentList.add(student2);studentList.add(student3);studentService.saveOrUpdateBatch(studentList);}/*** 批量删除*/@Testvoid contextLoadDeleteBatch() {List<Student> studentList=new ArrayList<>();Student student1 = new Student("123456","刘品水",18);Student student2 = new Student("654321","刘品水",18);Student student3 = new Student("77777","刘品水",18);studentList.add(student1);studentList.add(student2);studentList.add(student3);studentService.deleteBatch(studentList);}/*** 删除所有*/@Testvoid contextLoadDeleteBatchAll() {studentService.deleteAll();}}

六、总结

本文介绍了如何结合 MyBatis-Plus 和达梦数据库来实现高效的数据持久化操作。通过配置数据源、创建实体类、Mapper 接口和 Service 层，我们可以轻松地完成增删改查等数据库操作。MyBatis-Plus 的强大功能和简便的操作方式，大大提高了开发效率，使得数据持久化变得更加轻松愉快。

最重要的就是实体类上要记得加上你的模式名