01.快速开始
快速开始
数据库表
现有一张 User 表，其对应的数据库 Schema 脚本如下：
DROP TABLE IF EXISTS user;
CREATE TABLE user
(
id BIGINT(20) NOT NULL COMMENT '主键ID',
name VARCHAR(30) NULL DEFAULT NULL COMMENT '姓名',
age INT(11) NULL DEFAULT NULL COMMENT '年龄',
email VARCHAR(50) NULL DEFAULT NULL COMMENT '邮箱',
PRIMARY KEY (id)
);
其对应的数据库 Data 脚本如下：
DELETE FROM user;
INSERT INTO user (id, name, age, email) VALUES
(1, 'Jone', 18, 'test1@baomidou.com'),
(2, 'Jack', 20, 'test2@baomidou.com'),
(3, 'Tom', 28, 'test3@baomidou.com'),
(4, 'Sandy', 21, 'test4@baomidou.com'),
(5, 'Billie', 24, 'test5@baomidou.com');
依赖配置
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter</artifactId>
</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>Latest Version</version>
</dependency>
<dependency>
<groupId>com.h2database</groupId>
<artifactId>h2</artifactId>
<scope>runtime</scope>
</dependency>
</dependencies>
在 application.yml 配置文件中添加 H2 数据库的相关配置：
# DataSource Config
spring:
datasource:
driver-class-name: org.h2.Driver
schema: classpath:db/schema-h2.sql
data: classpath:db/data-h2.sql
url: jdbc:h2:mem:test
username: root
password: test
在 Spring Boot 启动类中添加 @MapperScan 注解，扫描 Mapper 文件夹：
@SpringBootApplication
@MapperScan("com.baomidou.mybatisplus.samples.quickstart.mapper")
public class Application {
public static void main(String[] args) {
SpringApplication.run(QuickStartApplication.class, args);
}
}
编码
编写实体类 User.java：
@Data
public class User {
private Long id;
private String name;
private Integer age;
private String email;
}
编写 Mapper 类 UserMapper.java：
public interface UserMapper extends BaseMapper<User> {
}
添加测试类，进行功能测试：
@RunWith(SpringRunner.class)
@SpringBootTest
public class SampleTest {
@Autowired
private UserMapper userMapper;
@Test
public void testSelect() {
System.out.println(("----- selectAll method test ------"));
List<User> userList = userMapper.selectList(null);
Assert.assertEquals(5, userList.size());
userList.forEach(System.out::println);
}
}
UserMapper 中的 selectList() 方法的参数为 MP 内置的条件封装器 Wrapper，所以不填写就是无任何条件。
Service 案例
mp 框架同样提供了 service 层的封装支持，让我们能够简化 service 层的开发；service 接口继承 IService，service 实现类继承 ServiceImpl，IService 提供了所有通用常用的方法，包括批处理添加更新支持，以及 lambda 支持；DepartmentService 继承 IService：
public interface DepartmentService extends IService<Department> {
}
@Service("departmentService")
public class DepartmentServiceImpl extends ServiceImpl<DepartmentMapper,Department> implements DepartmentService {
}
@RunWith(SpringRunner.class)
@SpringBootTest
public class DepartmentServiceTest {
@Autowired
private DepartmentService departmentService;
/**
* 添加测试
*/
@Test
public void save(){
Department department=new Department();
department.setName("牛逼");
department.setRemark("xxx");
boolean save = departmentService.save(department);
System.out.println(save);
}
/**
* 修改测试
*/
@Test
public void updateById(){
Department department=new Department();
department.setId(9);
department.setName("牛逼2");
department.setRemark("xxx2");
boolean save = departmentService.updateById(department);
System.out.println(save);
}
/**
* 删除
*/
@Test
public void removeById(){
boolean b = departmentService.removeById(9);
System.out.println(b);
}
/**
* 查询
*/
@Test
public void list(){
List<Department> list = departmentService.list();
System.out.println(list);
}
/**
* 批量添加
*/
@Test
public void saveBatch(){
Department department1=new Department();
department1.setName("牛逼1");
department1.setRemark("xxx1");
Department department2=new Department();
department2.setName("牛逼2");
department2.setRemark("xxx2");
Department department3=new Department();
department3.setName("牛逼3");
department3.setRemark("xxx3");
boolean b = departmentService.saveBatch(Arrays.asList(department1, department2, department3));
System.out.println(b);
}
/**
* 批量添加或者更新
*/
@Test
public void saveOrUpdateBatch(){
Department department1=new Department();
department1.setName("牛逼4");
department1.setRemark("xxx4");
Department department2=new Department();
department2.setId(11);
department2.setName("牛逼2x");
department2.setRemark("xxx2x");
boolean b = departmentService.saveOrUpdateBatch(Arrays.asList(department1, department2));
System.out.println(b);
}
}