31|31,springboot 整合 Mybatis-Plus 31|springboot整合Mybatis-Plus

【31|31,springboot 整合 Mybatis-Plus】Mybatis-Plus是一个Mybatis的增强工具，它在Mybatis的基础上做了增强，却不做改变。我们在使用Mybatis-Plus之后既可以使用Mybatis-Plus的特有功能，又能够正常使用Mybatis的原生功能。Mybatis-Plus(以下简称MP)是为简化开发、提高开发效率而生，但它也提供了一些很有意思的插件，比如SQL性能监控、乐观锁、执行分析等。
mybatis-plus 官网 https://baomidou.oschina.io/mybatis-plus-doc/#/
1 集成依赖，pom中加入依赖即可

com.baomidou mybatisplus-spring-boot-starter 1.0.5 com.baomidou mybatis-plus 2.3 org.mybatis.spring.boot mybatis-spring-boot-starter 1.3.1

2，application.yml 添加 Mybatis-Plus 配置

spring: datasource: # type: com.alibaba.druid.pool.DruidDataSource driver-class-name: com.mysql.jdbc.Driver url: jdbc:mysql://localhost:3306/sd_roulette?useUnicode=true&characterEncoding=utf8&autoReconnect=true&allowMultiQueries=tru username: root password: root mybatis-plus: global-config: #主键类型0:"数据库ID自增", 1:"用户输入ID",2:"全局唯一ID (数字类型唯一ID)", 3:"全局唯一ID UUID"; id-type: 0

3，实体类Users代码如下

package com.weiye.mapperplus.entity; import com.baomidou.mybatisplus.annotations.TableField; import com.baomidou.mybatisplus.annotations.TableId; import com.baomidou.mybatisplus.annotations.TableName; import com.baomidou.mybatisplus.enums.IdType; import javax.persistence.*; @TableName("users")//@TableName 是指与数据库的关联，意味着表对应的数据库表名是users public class Users { @TableId(value="https://www.it610.com/article/id",type= IdType.AUTO)//确认为主键 private Integer id; @TableField("username")//@TableField表示表中的有个属性 private String username; @TableField("password")//@TableField表示表中的有个属性 privateString password; publicUsers () { } public Users(Integer id, String username, String password) { this.id = id; this.username = username; this.password = password; } public Users(String username, String password) { this.username = username; this.password = password; },,,,,,,,//省去set/get }

4,新增一个MybatisPlus配置类，放在config包下，其中没有做过多的设置，只是设置了一下方言，代码如下：

package com.weiye.mapperplus.config; import com.baomidou.mybatisplus.plugins.PaginationInterceptor; import org.mybatis.spring.annotation.MapperScan; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Configuration; @Configuration @MapperScan(value = "https://www.it610.com/article/com.weiye.mapperplus.mapper")//扫描的mapper包,必须写 public class MybatisPlusConfig { @Bean public PaginationInterceptor paginationInterceptor(){ PaginationInterceptor page = new PaginationInterceptor(); //设置方言类型 page.setDialectType("mysql"); return page; } }

5，在mapper里添加UserMapper接口继承了MybatisPlus的BaseMapper

package com.weiye.mapperplus.mapper; import com.baomidou.mybatisplus.mapper.BaseMapper; import com.weiye.mapperplus.entity.Users; public interface UserMapper extends BaseMapper { @Select("select * from users") List getUserList(); //普通的mybatis 查询 Mybatis-Plus 只是对mybatis进行增强 }

6，新建UsersController 类进行测试

package com.weiye.mapperplus.controller; import com.baomidou.mybatisplus.mapper.EntityWrapper; import com.baomidou.mybatisplus.plugins.Page; import com.weiye.mapperplus.entity.Users; import com.weiye.mapperplus.mapper.UserMapper; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RestController; import java.util.HashMap; import java.util.List; import java.util.Map; @RestController public class UserController { /**思路:1，配置一个config ,2.添加2个mybatis-plus的jar包，和mybatis的jar ，3，maopper借口继承BaseMapper接口* 4，controller写接口代码*/ @Autowired private UserMapper userDao; //http://localhost:8080/getUserList @RequestMapping("/getUserList")//普通的mybatis 查询 Mybatis-Plus 只是对mybatis进行增强 public List getUserList(){ return userDao.getUserList(); } //http://localhost:8080/getUserListByName?username=xiaoli //条件查询 @RequestMapping("/getUserListByName") public List getUserListByName(String username) { Map map = new HashMap(); map.put("username", username); return userDao.selectByMap(map); } //http://localhost:8080/saveUser?username=xiaoli&userPassword=111 //保存用户 @RequestMapping("/saveUser") public Users saveUser(Integer id, String username, String password){ Users user = new Users(id,username,password); userDao.insert(user); returnuser; } //http://localhost:8080/updateUser?id=5&username=xiaoli&userPassword=111 //修改用户 @RequestMapping("/updateUser") public String updateUser(Integer id,String userName,String userPassword) { Users user = new Users(id,userName,userPassword); Integer index = userDao.updateById(user); if(index>0){ return "修改用户成功，影响行数"+index+"行。"; }else{ return "修改用户失败，影响行数"+index+"行。"; } } //http://localhost:8080/getUserById?userId=1 //根据Id查询User @RequestMapping("/getUserById") public Users getUserById(Integer userId){ return userDao.selectById(userId); } //http://localhost:8080/getUserListByPage?pageNumber=1&pageSize=2 //条件分页查询 @RequestMapping("/getUserListByPage") public List getUserListByPage(Integer pageNumber,Integer pageSize){ //方法一： List userList = userDao.selectPage( new Page(1, 10), new EntityWrapper().eq("username", "li") ); returnuserList; //方法二 Page page =new Page<>(pageNumber,pageSize); EntityWrapper entityWrapper = new EntityWrapper<>(); entityWrapper.eq("username", "xiaoli"); return userDao.selectPage(page,entityWrapper); */ } //http://localhost:8080/deleteUserById?userId=1 //根据Id进行删除 @RequestMapping("/deleteUserById") public Integer deleteUserById(Integer userId) { return userDao.deleteById(userId); } //http://localhost:8080/deleteUserListByName?username=xiaoyi//条件删除@RequestMapping("/deleteUserListByName")public Integer deleteUserListByName(String username){ Map map = new HashMap(); map.put("username", username); return userDao.deleteByMap(map); }}