Spring Boot（二）jpa操作数据库

application.yml配置：

spring:
  # 数据库连接
  datasource:
    url: jdbc:mysql://192.168.1.200:3306/demo?serverTimezone=UTC&useUnicode=true&characterEncoding=utf8&useSSL=false
    username: root
    password: 123456
    driver-class-name: com.mysql.cj.jdbc.Driver
  # jpa配置
  jpa:
    show-sql: true

# 自定义配置类
blog:
  name: cqrunnerxjzh
  address: https://www.cnblogs.com/gaoqiao/

pom.xml配置

<!--Lombox使用-->
<dependency>
    <groupId>org.projectlombok</groupId>
    <artifactId>lombok</artifactId>
    <optional>true</optional>
    <version>1.18.2</version>
</dependency>
<!--数据库操作-->
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>
<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
</dependency>
<dependency>
    <groupId>com.jayway.jsonpath</groupId>
    <artifactId>json-path</artifactId>
</dependency>

读取yml的内容：

@Component
@Data
public class BlogProperties {

    @Value("${blog.name}")
    private String blogName;

    @Value("${blog.address}")
    private String blogAddress;

}

@Test
public void getBlogProperties() {
    System.out.println(blogProperties.getBlogName()+" and "+blogProperties.getBlogAddress());
}

运行效果：

实体类：

@Entity
@Data
public class DeptInfo implements Serializable {

    private static final long serialVersionUID = 1L;

    /**
     * 部门ID，自动增长+1
     */
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long deptId;
    /**
     * 部门名称
     */
    private String deptName;
    /**
     * 备注
     */
    private String remark;
}

dao层：

@Repository
public interface DeptRepository extends JpaRepository<DeptInfo, Long> {
    DeptInfo findByDeptId(Long id);

    DeptInfo findByDeptIdAndDeptName(Long id, String deptName);
}

测试：

@RunWith(SpringRunner.class)
@SpringBootTest
public class DeptRepositoryTests {
    @Autowired
    private DeptRepository deptRepository;

    @Autowired
    private BlogProperties blogProperties;

    @Test
    public void findByDeptId() {
        DeptInfo deptInfo = deptRepository.findByDeptId(1L);
        System.out.println(deptInfo);
    }

    @Test
    public void findByDeptIdAndDeptName() {
        DeptInfo deptInfo = deptRepository.findByDeptIdAndDeptName(1L,"研发部");
        System.out.println(deptInfo);
    }

    @Test
    public void saveDept() {
        DeptInfo deptInfo = new DeptInfo();
        deptInfo.setDeptName("行政");
        deptInfo.setRemark("jpa add");
        System.out.println(deptRepository.save(deptInfo));
    }

    @Test
    public void getBlogProperties() {
        System.out.println(blogProperties.getBlogName()+" and "+blogProperties.getBlogAddress());
    }
}

controller层：

@RestController
public class HelloWorldController {
    @RequestMapping("/getDept")
    public DeptInfo getDept() {
        DeptInfo deptInfo = new DeptInfo();
        deptInfo.setDeptId(1L);
        deptInfo.setDeptName("研发部");
        deptInfo.setRemark("测试专用");
        return deptInfo;
    }
}

运行效果：http://localhost:8080/getDept

以上操作中，遇到的报错，解决办法如下：

解决引入jpa报错

Lombok使用

com.mysql.jdbc.Driver与com.mysql.cj.jdbc.Driver的区别

 springBoot jpa主键策略

参考原文：https://www.cnblogs.com/ityouknow/p/5730412.html （纯洁的微笑）