SpringBoot连接MySQL并整合MyBatis-Plus

一、配置MySQL数据库和MyBatis-Plus依赖

<dependencies><!-- 导入MySQL依赖 --><dependency><groupId>mysql</groupId><artifactId>mysql-connector-java</artifactId><version>8.0.28</version></dependency><!-- 导入Mybatis-Plus依赖 --><dependency><groupId>com.baomidou</groupId><artifactId>mybatis-plus-boot-starter</artifactId><version>3.4.0</version></dependency><!-- 导入lombok依赖 --><dependency><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId><scope>provided</scope></dependency></dependencies><build><plugins><plugin><groupId>org.springframework.boot</groupId><artifactId>spring-boot-maven-plugin</artifactId></plugin></plugins><!-- 将java目录下的xml文件、resources目录中的静态文件进行编译 --><resources><resource><directory>src/main/java</directory><includes><include>**/*.xml</include></includes><filtering>true</filtering></resource><resource><directory>src/main/resources</directory><includes><include>**/*.*</include></includes></resource></resources></build>

二、配置yml文件中MySQL的连接和Mybatis-Plus配置

spring:#  mysql配置信息datasource:#                 数据库地址  端口  数据库名url: jdbc:mysql://127.0.0.1:3306/springboot_demo?useUnicode=true&characterEncoding=utf-8&useSSL=true&serverTimezone=GMT%2B8username: root    # 账号password: root    # 密码driver-class-name: com.mysql.cj.jdbc.Driver
mybatis-plus:mapper-locations: mapper/*.xml#这个配置是用来连接mapper接口和mapper配置类的configuration:log-impl: org.apache.ibatis.logging.stdout.StdOutImpl #运行日志map-underscore-to-camel-case:true#驼峰转换type-aliases-package: com.example.springbootdemo.model #实体类扫描包

三、创建一个测试表并添加数据

四、测试使用MyBatis-Plus 查询数据

1、创建实体类

packagecom.example.springbootdemo.model;importcom.baomidou.mybatisplus.annotation.*;importcom.fasterxml.jackson.annotation.JsonFormat;importlombok.Data;importjava.util.Date;/**
 * @ClassName: User
 * @Description:
 * @Author: WangBin
 * @Date: 2023/6/17 20:48
 */@Data@TableName("user")publicclassUser{/** id */@TableId(value ="id", type =IdType.AUTO)privateInteger id;/** 名字 */privateString name;/** 账号 */privateString account;/** 密码 */privateString password;/** 创建者 */privateString createBy;/** 创建时间 */@JsonFormat(pattern ="yyyy-MM-dd HH:mm:ss")// 规定时间数据格式privateDate createTime;/** 更新者 */privateString updateBy;/** 更新时间 */@JsonFormat(pattern ="yyyy-MM-dd HH:mm:ss")// 规定时间数据格式privateDate updateTime;/** 备注 */privateString remark;}

2、创建Controller

packagecom.example.springbootdemo.controller;importcom.example.springbootdemo.model.User;importcom.example.springbootdemo.service.UserService;importorg.springframework.beans.factory.annotation.Autowired;importorg.springframework.web.bind.annotation.*;importjava.util.List;/**
 * @ClassName: UserController
 * @Description:
 * @Author: WangBin
 * @Date: 2023/6/17 21:07
 */@RestControllerpublicclassUserController{@AutowiredprivateUserService userService;/**
     * 根据ID查询用户(使用MyBatis-Plus方法查询)
     * @param userId
     * @return
     */@RequestMapping(value ="/queryUserById/{userId}", method =RequestMethod.GET)publicUserqueryUserById(@PathVariable("userId")Integer userId){User user = userService.getById(userId);return user;}/**
     * 条件查询(使用MyBatis-Plus方法查询)
     * @param user
     * @return
     */@RequestMapping(value ="/getList", method =RequestMethod.POST)publicList<User>getList(@RequestBodyUser user){List<User> list = userService.getList(user);return list;}/**
     * 根据姓名查询用户
     * @param name
     * @return
     */@RequestMapping(value ="/getUserByName",method =RequestMethod.GET)publicList<User>getUserByName(@RequestParam("name")String name){List<User> users = userService.getUserByName(name);return users;}/**
     * 根据账号查询用户
     * @param account
     * @return
     */@RequestMapping(value ="/getUserByAccount",method =RequestMethod.GET)publicUsergetUserByAccount(@RequestParam("account")String account){User user = userService.getUserByAccount(account);return user;}}

3、创建service接口

packagecom.example.springbootdemo.service;importcom.baomidou.mybatisplus.extension.service.IService;importcom.example.springbootdemo.model.User;importjava.util.List;/**
 * @ClassName: UserService
 * @Description:
 * @Author: WangBin
 * @Date: 2023/6/17 21:09
 */publicinterfaceUserServiceextendsIService<User>{/**
     * 条件查询
     * @param user
     * @return
     */List<User>getList(User user);/**
     * 根据姓名查询用户
     * @param name
     * @return
     */List<User>getUserByName(String name);/**
     * 根据账号查询用户
     * @param account
     * @return
     */UsergetUserByAccount(String account);}

4、创建Service实现类

packagecom.example.springbootdemo.service.impl;importcom.baomidou.mybatisplus.core.conditions.query.QueryWrapper;importcom.baomidou.mybatisplus.extension.service.impl.ServiceImpl;importcom.example.springbootdemo.mapper.UserMapper;importcom.example.springbootdemo.model.User;importcom.example.springbootdemo.service.UserService;importorg.springframework.beans.factory.annotation.Autowired;importorg.springframework.stereotype.Service;importjava.util.List;/**
 * @ClassName: UserServiceImpl
 * @Description:
 * @Author: WangBin
 * @Date: 2023/6/17 21:10
 */@ServicepublicclassUserServiceImplextendsServiceImpl<UserMapper,User>implementsUserService{@AutowiredprivateUserMapper userMapper;/**
     * 条件查询
     * @param user
     * @return
     */@OverridepublicList<User>getList(User user){QueryWrapper<User> wrapper =newQueryWrapper<>();if(user.getId()!=null&& user.getId()>0){
            wrapper.eq("id",user.getId());}if(user.getName()!=null&& user.getName()!=""){
            wrapper.like("name",user.getName());}// .....List<User> list = userMapper.selectList(wrapper);return list;}/**
     * 根据姓名查询用户
     * @param name
     * @return
     */@OverridepublicList<User>getUserByName(String name){List<User> list = userMapper.getUserByName(name);return list;}@OverridepublicUsergetUserByAccount(String account){User user = userMapper.getUserByAccount(account);return user;}}

5、创建Mapper

packagecom.example.springbootdemo.mapper;importcom.baomidou.mybatisplus.core.mapper.BaseMapper;importcom.example.springbootdemo.model.User;importorg.apache.ibatis.annotations.Mapper;importorg.apache.ibatis.annotations.Param;importorg.apache.ibatis.annotations.Select;importjava.util.List;/**
 * @ClassName: UserMapper
 * @Description:
 * @Author: WangBin
 * @Date: 2023/6/17 20:27
 */@MapperpublicinterfaceUserMapperextendsBaseMapper<User>{@Select("select * from `user` where name=#{name}")List<User>getUserByName(@Param("name")String name);UsergetUserByAccount(@Param("account")String account);}

6、创建Mapper配置类

<?xml version="1.0" encoding="UTF-8"?><!DOCTYPE mapper
        PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN""http://mybatis.org/dtd/mybatis-3-mapper.dtd"><mapper namespace="com.example.springbootdemo.mapper.UserMapper"><select id="getUserByAccount" parameterType="java.lang.String" resultType="com.example.springbootdemo.model.User">
        select * from `user` where account=#{account}</select></mapper>

五、接口测试

1、URL携带参数测试(通过\绑定)

2、POST请求体测试

3、URL携带参数测试(通过?绑定)