springboot+mybatis_plus的使用
项目码云地址：https://gitee.com/XiangWenTian001/mybatis_plus
新建user表
CREATE TABLE `user` (
`id` int(10) NOT NULL AUTO_INCREMENT,
`user_name` varchar(255) NOT NULL,
`password` varchar(255) NOT NULL,
`phone` varchar(19) NOT NULL,
`age` int(3) NOT NULL,
`address` varchar(255) DEFAULT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=115 DEFAULT CHARSET=utf8;
com.baomidou
mybatis-plus-boot-starter
3.1.0
整个pom.xml
4.0.0
org.springframework.boot
spring-boot-starter-parent
2.1.5.RELEASE
com.mybatisplus
demo
0.0.1-SNAPSHOT
demo
Demo project for Spring Boot
1.8
org.springframework.boot
spring-boot-starter-web
mysql
mysql-connector-java
org.projectlombok
lombok
true
org.springframework.boot
spring-boot-starter-test
test
com.baomidou
mybatis-plus-boot-starter
3.1.0
org.springframework.boot
spring-boot-maven-plugin
application.yml中配置mybatis_plus
server:
port: 8080
spring:
datasource:
username: root
password: 123456
driver-class-name: com.mysql.cj.jdbc.Driver
url: jdbc:mysql://125.25.3.39:3306/testdb?characterEncoding=utf-8
mybatis-plus:
mapper-locations: classpath:/mapper/*Mapper.xml
typeAliasesPackage: com.mybatisplus.demo.entity
configuration:
#配置返回数据库(column下划线命名&&返回java实体是驼峰命名)，自动匹配无需as（没开启这个，SQL需要写as： select user_id as userId）
map-underscore-to-camel-case: true
log-impl: org.apache.ibatis.logging.stdout.StdOutImpl
global-config:
db-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: NONE
实体类 @Data是loombook插件，需要导入相应jar包，可自行学习
@Data
public class User {
private Integer id;
private String userName;
private String password;
private String address;
private String phone;
private Integer age;
}
userMapper中
@Mapper
public interface UserMapper extends BaseMapper {
} userMapper继承了BaseMapper，一些通用的增删该查根本不用我们写了，有些类似于jpa。
多表操作时，个人觉得还是和原始方式一样建立xml文件操作方便点，注解方式不是很明晰。
测试：
package com.mybatisplus.demo;
import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.baomidou.mybatisplus.core.conditions.update.UpdateWrapper;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.mybatisplus.demo.dao.UserMapper;
import com.mybatisplus.demo.entity.User;
import com.mybatisplus.demo.vo.UserArticleVo;
import org.junit.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.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
/**
* CREATE TABLE `user` (
* `id` int(10) NOT NULL AUTO_INCREMENT,
* `user_name` varchar(255) NOT NULL,
* `password` varchar(255) NOT NULL,
* `phone` varchar(19) NOT NULL,
* `age` int(3) NOT NULL,
* `address` varchar(255) DEFAULT NULL,
* PRIMARY KEY (`id`)
* ) ENGINE=InnoDB AUTO_INCREMENT=65 DEFAULT CHARSET=utf8;
*/
@RunWith(SpringRunner.class)
@SpringBootTest
public class UserMapperTests {
@Autowired
private UserMapper userDao;
/****************************************insert***************************************************************************/
@Test
public void testAdd() {
for (int i = 0; i < 50; i++) {
User user = new User();
user.setAddress("杭州市下城区小区路33号==" + i);
user.setAge(i);
user.setPassword("admin" + i);
user.setUserName("admin" + i);
user.setPhone("18900994378=" + i);
userDao.insert(user);
}
}
/****************************************update***************************************************************************/
/**
* 传值为null不会更新
*/
@Test
public void testUpdate1() {
User user = new User();
user.setId(17);
user.setAddress(null);
user.setAge(129);
user.setPassword("admin11111");
user.setUserName("admin1111");
user.setPhone("18900994378");
//UPDATE user SET user_name=?, password=?, phone=?, age=? WHERE id=?
userDao.updateById(user);
}
/**
* 传值为空字符串会更新。
* pojo一定要设置成包装类，否则更新时会把默认值跟新掉，
* 如字段age设置成int类型，不传值时会将age更新为0，int默认值为0
*/
@Test
public void testUpdate2() {
User user = new User();
user.setId(17);
user.setAddress("");
user.setAge(129);
user.setPassword("admin11111");
user.setUserName("admin1111");
user.setPhone("18900994378");
//UPDATE user SET user_name=?, password=?, address=?, phone=?, age=? WHERE id=?
userDao.updateById(user);
}
/**
* 根据条件更新
*/
@Test
public void testUpdateWrapper() {
User user = new User();
user.setAddress("update999");
UpdateWrapper wrapper = new UpdateWrapper<>();
wrapper.eq("user_name", "admin");
//UPDATE user SET address=? WHERE user_name = ?
userDao.update(user, wrapper);
}
/****************************************delete***************************************************************************/
@Test
public void testDelete() {
userDao.deleteById(2);
}
@Test
public void testBatchDelete() {
List list = new ArrayList<>();
list.add(1);
list.add(3);
userDao.deleteBatchIds(list);
}
@Test
public void testMapDelete() {
Map map = new HashMap<>();
map.put("age", "1");
map.put("password", "admin1");
map.put("user_name", "admin1");
//DELETE FROM user WHERE password = ? AND user_name = ? AND age = ?
userDao.deleteByMap(map);
}
@Test
public void testWrapperDelete() {
//DELETE FROM user WHERE id = ?
userDao.delete(new UpdateWrapper().eq("id", "64"));
}
/****************************************select***************************************************************************/
/**
* 查询全部
*/
@Test
public void testGetAll() {
//SELECT id,user_name,password,address,phone,age FROM user
List list = userDao.selectList(null);
list.stream().forEach(user -> System.out.println(user));
}
/**
* 根据id批量查询
*/
@Test
public void testSelectBatchIds() {
List idList = new ArrayList<>();
idList.add(11);
idList.add(32);
//SELECT id,user_name,password,address,phone,age FROM user WHERE id IN ( ? , ? ) Parameters: 11(Integer), 32(Integer)
List list = userDao.selectBatchIds(idList);
list.stream().forEach(user -> System.out.println(user));
}
/**
* map构造条件查询
*/
@Test
public void testdSele1ctByMap() {
Map map = new HashMap<>();
map.put("id", "44");
map.put("password", "admin29");
////SELECT id,user_name,password,address,phone,age FROM user WHERE password = ? AND id = ?
List list = userDao.selectByMap(map);
list.stream().forEach(user -> System.out.println(user));
}
/**
* 实体类构造条件查询
*/
@Test
public void testdSelectList1() {
User user = new User();
user.setId(44);
user.setPhone("18900994378=29");
//SELECT id,user_name,password,address,phone,age FROM user WHERE id=? AND phone=?
List list = userDao.selectList(new QueryWrapper<>(user));
list.stream().forEach(u -> System.out.println(u));
}
/**
* QueryWrapper构造条件查询
*/
@Test
public void testSeleectList2() {
List userList = userDao.selectList(
new QueryWrapper().gt("age", "22")
);
//SELECT id,user_name,password,address,phone,age FROM user WHERE age > ?
userList.stream().forEach(u -> System.out.println(u));
}
/**
* 分页查询，逻辑分页，如果要物理分页需要注入PaginationInterceptor
*/
@Test
public void testdSeleectList3() {
List userList = userDao.selectPage(
new Page(1L, 8L),
null
).getRecords();
userList.stream().forEach(u -> System.out.println(u));
}
/**
* 部分字段查询
*/
@Test
public void testSelectList() {
//SELECT id,user_name,password FROM user
List userList = userDao.selectList(new QueryWrapper().select("id,user_name,password"));
userList.stream().forEach(user -> System.out.println(user));
}
/****************************************多表操作***************************************************************************/
@Test
public void testManyTable() {
Page page = new Page<>(1,7);
//SELECT u .id AS userId, u .user_name, u .address, u .phone, u .age, a.content, a.title FROM `user` u, article a WHERE u.id = a.user_id LIMIT ?,?
List list=userDao.getUserArticle(page);
list.stream().forEach(userArticleVo -> System.out.println(userArticleVo));
}
}
项目码云地址：https://gitee.com/XiangWenTian001/mybatis_plus