package com.nanfeng.getdata.config;
import com.baomidou.mybatisplus.extension.plugins.MybatisPlusInterceptor;
import com.baomidou.mybatisplus.extension.plugins.inner.PaginationInnerInterceptor;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
@Configuration
public class PageConfig {
/**
* 3.4.0之前的版本用这个
* @return
*/
/* @Bean
public PaginationInterceptor paginationInterceptor(){
return new PaginationInterceptor();
}*/
/**
* 3.4.0之后提供的拦截器的配置方式
*
* @return
*/
@Bean
public MybatisPlusInterceptor mybatisPlusInterceptor() {
MybatisPlusInterceptor mybatisPlusInterceptor = new MybatisPlusInterceptor();
mybatisPlusInterceptor.addInnerInterceptor(new PaginationInnerInterceptor());
return mybatisPlusInterceptor;
}
}
package com.nanfeng.getdata;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication
@MapperScan("com.nanfeng.getdata.mapper")
public class GetdataApplication {
public static void main(String[] args) {
SpringApplication.run(GetdataApplication.class, args);
}
}
package com.nanfeng.getdata.mapper;
import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.nanfeng.getdata.entity.User;
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Select;
@Mapper
public interface UserMapper extends BaseMapper<User> {
/**
* 这个sql写的有问题,mp实现多表操作其实就是这样实现的(或者建立xml映射文件)
* @return
*/
//@Select("select name, age from tb1,tb2 where id=1")
// public User selectManyTable();
}
# datasource
spring:
datasource:
url: jdbc:mysql:///mptest
username: root
password: root
driver-class-name: com.mysql.jdbc.Driver
mybatis-plus:
global-config:
db-config:
# 表名前缀
table-prefix: tb_
# id生成策略 数据库自增
#id-type: auto
#configuration:
# 日志
#log-impl: org.apache.ibatis.logging.stdout.StdOutImpl
# 枚举包
#type-enums-package: com.itheima.mp.enums
package com.itheima.mp;
import com.baomidou.mybatisplus.core.metadata.IPage;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.itheima.mp.entity.User;
import com.itheima.mp.mapper.UserMapper;
import org.junit.jupiter.api.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
@SpringBootTest
@RunWith(SpringRunner.class)
class UserMapperTest {
@Autowired
private UserMapper userMapper;
/**
* 根据id查询
*/
@Test
public void testSelectById() {
User user = userMapper.selectById("1");
System.out.println(user);
}
/**
* 添加
*/
@Test
public void testInsert() {
User user = new User();
user.setId("666666666");
//user.setUserName("itcast");
//user.setPassword("itheima");
int count = userMapper.insert(user);
System.out.println(count);
}
/**
* 删除
*/
@Test
public void testDelete() {
/*
//1. 根据id删除
int count = userMapper.deleteById(8L);
*/
/*
//2. 根据id集合批量删除
List ids = new ArrayList();
ids.add(6);
ids.add(7);
userMapper.deleteBatchIds(ids);
*/
//3. 根据map构造条件，删除
Map<String, Object> map = new HashMap<>();
//delete from tb_user where user_name = ? and age = ?
map.put("user_name","zhangsan");
map.put("age","18");
userMapper.deleteByMap(map);
}
/**
* 修改
*/
@Test
public void testUpdateById() {
User user = new User();
//user.setId(2L);
//user.setPassword("1111111");
int count = userMapper.updateById(user);
}
/**
* 分页查询：
* 1. 当前页码：currentPage
* 2. 每页显示条数：size
*
* 注意：使用mp的分页要设置一个拦截器！！！
*/
@Test
public void testSelectPage() {
int current = 1;//当前页码
int size = 2;//每页显示条数
IPage<User> page = new Page(current,size);
userMapper.selectPage(page,null);
List<User> records = page.getRecords();//当前页的数据
long pages = page.getPages();//总页数 2
long total = page.getTotal();//总记录数 4
System.out.println(records);
System.out.println(pages);
System.out.println(total);
}
}
<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.3.4.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.itheima</groupId>
<artifactId>mybatis_plus_springboot</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>mybatis_plus_springboot</name>
<properties>
<java.version>1.8</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter</artifactId>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.26</version>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<optional>true</optional>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>com.baomidou</groupId>
<artifactId>mybatis-plus-boot-starter</artifactId>
<version>3.4.0</version>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
