Java MyBatis Plus 整合 Sqlite

POM.xml

注意 MyBatis plus 和 Spring Boot 版本有要求，3 的 MyBatis-Plus 不能连接 Spring Boot4.x

<?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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>org.example</groupId>
    <artifactId>MyBatisPlysTest</artifactId>
    <version>1.0-SNAPSHOT</version>
    <properties>
        <maven.compiler.source>21</maven.compiler.source>
        <maven.compiler.target>21</maven.compiler.target>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    </properties>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>3.3.5</version>
    </parent>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.18.48</version>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>org.xerial</groupId>
            <artifactId>sqlite-jdbc</artifactId>
            <version>3.53.4.0</version>
            <scope>compile</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-jdbc</artifactId>
            <scope>compile</scope>
        </dependency>
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-spring-boot3-starter</artifactId>
            <version>3.5.7</version>
        </dependency>
    </dependencies>
    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>
</project>

创建数据库

application.yml

server:
  port: 8081

spring:
  datasource:
    driver-class-name: org.sqlite.JDBC
    url: jdbc:sqlite:app.db
  sql:
    init:
      mode: always # schema.sql

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

schema.sql

CREATE TABLE IF NOT EXISTS "user" (
  id INTEGER PRIMARY KEY AUTOINCREMENT,
  name TEXT,
  age INTEGER,
  sex TEXT
);

创建pojo和mapper

User

@TableName("user")
public class User {

    @TableId(type = IdType.AUTO)
    private Integer id;

    @TableField("name")
    private String name;

    @TableField("age")
    private Integer age;

    @TableField("sex")
    private String sex;

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public Integer getAge() {
        return age;
    }

    public void setAge(Integer age) {
        this.age = age;
    }

    public String getSex() {
        return sex;
    }

    public void setSex(String sex) {
        this.sex = sex;
    }
}

UserMapper.java

extends BaseMapper<User> 即实现 MyBatis-Plus 增删改查功能

package org.example.mapper;

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

@Mapper
public interface UserMapper extends BaseMapper<User> {

}

创建Controller

UserController.java

package org.example.controller;


import jakarta.annotation.Resource;
import org.example.mapper.UserMapper;
import org.example.pojo.User;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.bind.annotation.RestController;

import java.util.List;
import java.util.Random;

@RestController
@RequestMapping("/user")
public class UserController {
    Random random = new Random();

    @Autowired
    private UserMapper userMapper;

    @GetMapping
    public List<User> getUser() {
        return userMapper.selectList(null);
    }

    @GetMapping("/insert")
    public int insertUser(){
        User user = new User();
        user.setAge(random.nextInt(100));
        user.setName("user" + random.nextInt(100));
        user.setSex(random.nextBoolean() ? "男" : "女");
        System.out.println("插入前user.id = " + user.getId());  // must be null
        return userMapper.insert(user);
    }
}

main

package org.example;

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

@MapperScan("org.example.mapper")
@SpringBootApplication
public class Main {
    public  static void main(String[] args) {
        SpringApplication.run(Main.class, args);
    }
}