最近正在集成SpringBoot与MyBatis-plus,体验感很好啊
sql
CREATE TABLE `class` (
`id` int(11) NOT NULL AUTO_INCREMENT COMMENT '编号',
`name` varchar(30) DEFAULT NULL COMMENT '班级名',
`floor` int(3) DEFAULT NULL COMMENT '楼层',
`teacher_id` int(11) DEFAULT NULL COMMENT '老师编号(FK)',
PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=30 DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_general_ci COMMENT='班级信息表';
INSERT INTO `class` VALUES ('1', '1年级2班', '4', '2');
INSERT INTO `class` VALUES ('2', '1年级3班', '4', '2');
INSERT INTO `class` VALUES ('3', '2年级1班', '1', '4');
INSERT INTO `class` VALUES ('4', '2年级2班', '2', '5');
INSERT INTO `class` VALUES ('5', '2年级3班', '3', '6');
INSERT INTO `class` VALUES ('6', '3年级1班', '4', '7');
INSERT INTO `class` VALUES ('7', '3年级2班', '1', '8');
INSERT INTO `class` VALUES ('8', '3年级3班', '2', '9');
INSERT INTO `class` VALUES ('9', '4年级1班', '3', '10');
INSERT INTO `class` VALUES ('10', '4年级2班', '4', '11');
INSERT INTO `class` VALUES ('11', '4年级3班', '1', '12');
INSERT INTO `class` VALUES ('12', '5年级1班', '2', '13');
INSERT INTO `class` VALUES ('13', '5年级3班', '4', '15');
INSERT INTO `class` VALUES ('14', '6年级2班', '2', '17');
INSERT INTO `class` VALUES ('15', '6年级3班', '3', '18');
INSERT INTO `class` VALUES ('16', '1年级4班', '4', '99');
INSERT INTO `class` VALUES ('17', '2年级4班', '2', '99');
INSERT INTO `class` VALUES ('18', '3年级4班', '1', '99');
INSERT INTO `class` VALUES ('19', '4年级1班', '1', '20');
INSERT INTO `class` VALUES ('30', '4年级1班', '22', '20');
CREATE TABLE `teacher` (
`id` int(11) NOT NULL AUTO_INCREMENT COMMENT '编号',
`name` varchar(30) DEFAULT NULL COMMENT '名字',
`age` int(2) DEFAULT NULL COMMENT '年龄',
`title` varchar(30) DEFAULT NULL COMMENT '职称',
`manager` int(11) DEFAULT NULL COMMENT '上司编号(FK)',
`salary` int(6) DEFAULT NULL COMMENT '工资',
`comm` int(6) DEFAULT NULL COMMENT '奖金',
`gender` char(1) DEFAULT NULL COMMENT '性别',
`subject_id` int(11) DEFAULT NULL COMMENT '科目编号(FK)',
PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=21 DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_general_ci COMMENT='老师信息表';
INSERT INTO `teacher` VALUES ('1', '刘苍松', '55', '总监', '20', '10000', '5000', '男', '1');
INSERT INTO `teacher` VALUES ('2', '范传奇', '33', '三级讲师', '1', '3000', null, '男', '2');
INSERT INTO `teacher` VALUES ('3', '王克晶', '32', '一级讲师', '1', '8000', '3000', '女', '3');
INSERT INTO `teacher` VALUES ('4', '刘国斌', '29', '二级讲师', '1', '7300', '3400', '男', '4');
INSERT INTO `teacher` VALUES ('5', '成恒', '35', '三级讲师', '1', '5200', '4600', '男', '5');
INSERT INTO `teacher` VALUES ('6', '张皓岚', '33', '二级讲师', '1', '7800', '700', '男', '2');
INSERT INTO `teacher` VALUES ('7', '胡悦', '25', '一级讲师', '1', '9000', '2800', '女', '1');
INSERT INTO `teacher` VALUES ('8', '齐雷', '45', '总监', '20', '9800', '7800', '男', '3');
INSERT INTO `teacher` VALUES ('9', '王海涛', '44', '二级讲师', '8', '3100', '1200', '男', '4');
INSERT INTO `teacher` VALUES ('10', '张久军', '39', '一级讲师', '8', '2000', '6000', '男', '5');
INSERT INTO `teacher` VALUES ('11', '于健', '27', '二级讲师', '12', '3800', null, '男', '2');
INSERT INTO `teacher` VALUES ('12', '张立志', '34', '总监', '20', '13000', '900', '男', '3');
INSERT INTO `teacher` VALUES ('13', '吴华', '46', '总监', '20', '8700', '6900', '男', '5');
INSERT INTO `teacher` VALUES ('14', '李大帅', '29', '三级讲师', '13', '7000', null, '男', '1');
INSERT INTO `teacher` VALUES ('15', '田浩', '26', '二级讲师', '13', '5600', '1900', '男', '4');
INSERT INTO `teacher` VALUES ('16', '肖旭伟', '36', '一级讲师', '12', '6800', '600', '男', '2');
INSERT INTO `teacher` VALUES ('17', '张敏', '29', '三级讲师', '13', '6100', '400', '女', '3');
INSERT INTO `teacher` VALUES ('18', '赵微', '26', '二级讲师', '13', '4600', '6500', '女', '4');
INSERT INTO `teacher` VALUES ('19', '李源', '25', '三级讲师', '13', '6300', '0', '男', '4');
INSERT INTO `teacher` VALUES ('20', '韩少云', '55', '老板', null, '1', '0', '男', null);
pom.xml
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>8.0.28</version>
</dependency>
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>druid</artifactId>
<version>1.2.8</version>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<version>1.18.24</version>
</dependency>
<dependency>
<groupId>com.baomidou</groupId>
<artifactId>mybatis-plus-boot-starter</artifactId>
<version>3.5.3</version>
</dependency>
application.yml
spring:
# 数据库连接配置
datasource:
driver-class-name: com.mysql.cj.jdbc.Driver
type: com.alibaba.druid.pool.DruidDataSource
url: jdbc:mysql://localhost:3306/hedu?useSSL=false&serverTimeZone=Asia/Shanghai
username: root
password: root
# mybatis-plus配置
mybatis-plus:
mapper-locations: classpath:mappers/*.xml
configuration:
log-impl: org.apache.ibatis.logging.stdout.StdOutImpl
Mybatis-plus的分页插件的配置
package cn.highedu.boot.config;
import com.baomidou.mybatisplus.annotation.DbType;
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 MybatisPlusConfig {
/**
* 分页插件的配置
* @return
*/
@Bean
public MybatisPlusInterceptor paginationInterceptor(){
MybatisPlusInterceptor interceptor = new MybatisPlusInterceptor();
/**
* DbType.XXX
* XXX 为具体的数据库类型如MYSQL,ORACLE
*/
interceptor.addInnerInterceptor(new PaginationInnerInterceptor(DbType.MYSQL));
return interceptor;
}
}
创建基本类
Class
package cn.highedu.boot.entity;
import com.baomidou.mybatisplus.annotation.IdType;
import com.baomidou.mybatisplus.annotation.TableId;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
@Data
@AllArgsConstructor
@NoArgsConstructor
public class Class {
@TableId(type = IdType.AUTO)
private Integer id;
private String name;
private Integer floor;
private Integer teacherId;
}
ClassMapper
package cn.highedu.boot.mapper;
import cn.highedu.boot.entity.Class;
import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import org.apache.ibatis.annotations.*;
@Mapper
public interface ClassMapper extends BaseMapper<Class> {
}
ClassService
package cn.highedu.boot.service;
import cn.highedu.boot.entity.Class;
import com.baomidou.mybatisplus.extension.service.IService;
public interface ClassService extends IService<Class> {
}
ClassServiceImpl
package cn.highedu.boot.service.impl;
import cn.highedu.boot.entity.Class;
import cn.highedu.boot.mapper.ClassMapper;
import cn.highedu.boot.service.ClassService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import org.springframework.stereotype.Service;
@Service
public class ClassServiceImpl extends ServiceImpl<ClassMapper, Class> implements ClassService {
}
teacher
package cn.highedu.boot.entity;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
@Data
@AllArgsConstructor
@NoArgsConstructor
public class Teacher {
private Integer id;
private String name;
private Integer age;
private String title;
private Integer manager;
private Integer salary;
private Integer comm;
private Character gender;
private Integer subjectId;
}
TeacherMapper
package cn.highedu.boot.mapper;
import cn.highedu.boot.entity.Teacher;
import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import org.apache.ibatis.annotations.*;
@Mapper
public interface TeacherMapper extends BaseMapper<Teacher> {
}
TeacherService
package cn.highedu.boot.service;
import cn.highedu.boot.entity.Teacher;
import com.baomidou.mybatisplus.extension.service.IService;
public interface TeacherService extends IService<Teacher> {
}
TeacherServiceImpl
package cn.highedu.boot.service.impl;
import cn.highedu.boot.entity.Teacher;
import cn.highedu.boot.mapper.TeacherMapper;
import cn.highedu.boot.service.TeacherService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import org.springframework.stereotype.Service;
@Service
public class TeacherServiceImpl extends ServiceImpl<TeacherMapper, Teacher> implements TeacherService {
}
单表操作
SingleTableOperationTest
package cn.highedu.boot.service;
import cn.highedu.boot.entity.Class;
import cn.highedu.boot.mapper.ClassMapper;
import cn.highedu.boot.service.impl.ClassServiceImpl;
import com.baomidou.mybatisplus.core.conditions.query.LambdaQueryWrapper;
import com.baomidou.mybatisplus.core.toolkit.Wrappers;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import java.util.List;
@SpringBootTest
class ClassServiceTest extends ClassServiceImpl {
@Autowired
private ClassMapper classMapperSimple;
//基本操作
//insert
/**
* 新增一条记录
*/
@Test
void simpleAddOne(){
Class addOneClazz = new Class();
addOneClazz.setName("4年级1班");
addOneClazz.setFloor(22);
addOneClazz.setTeacherId(20);
//INSERT INTO class ( name, floor, teacher_id ) VALUES ( ?, ?, ? )
int addOneResult = classMapperSimple.insert(addOneClazz);
System.out.println(addOneResult);
}
//delete
/**
* 根据Id删除一条记录
*/
@Test
void simpleDeleteOneById(){
//DELETE FROM class WHERE id=?
int deleteByIdResult = classMapperSimple.deleteById(1);
System.out.println(deleteByIdResult);
}
//update
/**
* 根据Id更改一条记录
*/
@Test
void simpleUpdateOneById(){
Class updateClass = new Class();
updateClass.setId(2);
updateClass.setName("1年级3班");
updateClass.setFloor(4);
updateClass.setTeacherId(2);
//UPDATE class SET name=?, floor=?, teacher_id=? WHERE id=?
int updateByIdResult = classMapperSimple.updateById(updateClass);
System.out.println(updateByIdResult);
}
//select
/**
* 根据Id查询一条记录
*/
@Test
void simpleQueryOneById(){
//SELECT id,name,floor,teacher_id FROM class WHERE id=?
Class queryOneClass = classMapperSimple.selectById(1);
System.out.println(queryOneClass);
}
/**
* 查询所有记录
*/
@Test
void simpleQueryAll() {
//SELECT id,name,floor,teacher_id FROM class
List<Class> queryClasses = classMapperSimple.selectList(null);
System.out.println(queryClasses);
}
/**
*| 函数名 | 说明 |
*| ----------- | ----------- |
*| eq | 等于 |
*| ne | 不等 |
*| gt | 大于 |
*| it | 小于 |
*| between | 在值1到值2之间 |
*| like | 模糊查询 |
*| isNull | 字段为NULL |
*/
@Autowired
private ClassMapper classMapperComplex;
//进阶操作
//单表操作
//select
/**
* 根据Id查询条数据
*/
@Test
void complexQueryOne(){
LambdaQueryWrapper<Class> queryWrapper = Wrappers.lambdaQuery();
queryWrapper.eq(Class::getId, 1);
//SELECT id,name,floor,teacher_id FROM class WHERE (id = ?);
Class complexQueryOne = classMapperComplex.selectOne(queryWrapper);
System.out.println(complexQueryOne);
}
/**
* 查询相同条件的数据
*/
@Test
void complexQueryAll(){
LambdaQueryWrapper<Class> queryWrapper = Wrappers.lambdaQuery();
queryWrapper.eq(Class::getFloor,1);
//SELECT id,name,floor,teacher_id FROM class WHERE (floor = ?);
List<Class> complexQueryAll = classMapperComplex.selectList(queryWrapper);
System.out.println(complexQueryAll);
}
/**
* 查询范围内的数据
*/
@Test
void complexBetweenQuery(){
LambdaQueryWrapper<Class> queryWrapper = Wrappers.lambdaQuery();
queryWrapper.between(Class::getFloor,1,3);
//SELECT id,name,floor,teacher_id FROM class WHERE (floor BETWEEN ? AND ?);
List<Class> complexQueryAll = classMapperComplex.selectList(queryWrapper);
System.out.println(complexQueryAll);
}
/**
* 模糊查询
* like():前后加百分号,如 %1年级%
* likeLeft():前面加百分号,如 %1年级
* likeRight():后面加百分号,如 1年级%
*/
@Test
void complexLikeQuery(){
LambdaQueryWrapper<Class> queryWrapper = Wrappers.lambdaQuery();
queryWrapper.likeRight(Class::getName,"1年级");
// SELECT id,name,floor,teacher_id FROM class WHERE (name LIKE ?);
List<Class> complexLikeQuery = classMapperComplex.selectList(queryWrapper);
System.out.println(complexLikeQuery);
}
/**
* 按照楼层升序排列,从小到大
*/
@Test
void complexOrderQuery(){
LambdaQueryWrapper<Class> queryWrapper = Wrappers.lambdaQuery();
//condition ：条件，返回boolean，当condition为true，进行排序，如果为false，则不排序
//isAsc：是否为升序，true为升序，false为降序
//columns：需要操作的列
queryWrapper.orderBy(true,true,Class::getFloor);
List<Class> complexOrderByAscQuery= classMapperComplex.selectList(queryWrapper);
System.out.println(complexOrderByAscQuery);
}
/**
* 分页查询
*/
@Test
void complexPageQuery(){
Page<Class> page = new Page<>(1,3);
classMapperComplex.selectPage(page, null);
System.out.println(page.getRecords());//每页数据list集合
System.out.println(page.getCurrent());//当前页
System.out.println(page.getSize());//每页显示记录数
System.out.println(page.getTotal());//总记录数
System.out.println(page.getPages());//总页数
System.out.println(page.hasPrevious());//上一页
System.out.println(page.hasNext());//下一页
}
}
多表操作
MultipleTableOperationTest
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