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
<dependency>
<groupId>com.baomidou</groupId>
<artifactId>mybatisplus-spring-boot-starter</artifactId>
<version>1.0.5</version>
</dependency>
<dependency>
<groupId>com.baomidou</groupId>
<artifactId>mybatis-plus</artifactId>
<version>2.3</version>
</dependency>
<dependency>
<groupId>org.mybatis.spring.boot</groupId>
<artifactId>mybatis-spring-boot-starter</artifactId>
<version>1.3.1</version>
</dependency>
2，application.yml 添加 Mybatis-Plus 配置
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="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
private String password;
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 = "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<Users> {
@Select("select * from users")
List<Users> 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<Users> getUserList(){
return userDao.getUserList();
}
//http://localhost:8080/getUserListByName?username=xiaoli
//条件查询
@RequestMapping("/getUserListByName")
public List<Users> 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);
return user;
}
//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<Users> getUserListByPage(Integer pageNumber,Integer pageSize)
{
//方法一：
List<Users> userList = userDao.selectPage(
new Page<Users>(1, 10),
new EntityWrapper<Users>().eq("username", "li")
);
return userList;
//方法二
/*Page<Users> page =new Page<>(pageNumber,pageSize);
EntityWrapper<Users> 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);
}
}
