java - 当数据库不为空时,我从 findAll Spring 数据和 h2 数据库中获取空列表
问题描述
我有一个带有 h2 数据库的 spring boot API 项目。我在 data.sql 中添加了一些数据,但是数据没有插入到数据库中,但是当我调用 findAll API 时表创建成功,由于数据库表为空,我得到一个空列表。
应用程序属性
spring.datasource.url=jdbc:h2:mem:testdb
spring.datasource.driverClassName=org.h2.Driver
spring.datasource.username=sa
spring.datasource.password=password
spring.jpa.database-platform=org.hibernate.dialect.H2Dialect
server.port=8888
数据.sql
DROP TABLE IF EXISTS device;
DROP TABLE IF EXISTS gateway;
CREATE TABLE gateway (
id INT AUTO_INCREMENT PRIMARY KEY,
serial_number VARCHAR(250) UNIQUE,
name VARCHAR(250),
address VARCHAR(15) NOT NULL
);
CREATE TABLE device (
id INT AUTO_INCREMENT PRIMARY KEY,
UID INT UNIQUE,
vendor VARCHAR(250),
created DATE,
status BOOLEAN,
gateway_id INT,
FOREIGN KEY (gateway_id) REFERENCES gateway(id)
);
INSERT INTO gateway (id, serial_number, name, address) VALUES (1,'GTW-1','Gateway 1','123.187.65.1');
INSERT INTO gateway (id, serial_number, name, address) VALUES (2,'GTW-2','Gateway 2','123.187.65.2');
INSERT INTO gateway (id, serial_number, name, address) VALUES (3,'GTW-3','Gateway 3','123.187.65.3');
INSERT INTO gateway (id, serial_number, name, address) VALUES (4,'GTW-4','Gateway 4','123.187.65.4');
INSERT INTO device (id, UID, vendor, created, status, gateway_id) VALUES (1,001,'huawei', parsedatetime('17-09-2012', 'dd-MM-yyyy'), true, 1);
INSERT INTO device (id, UID, vendor, created, status, gateway_id) VALUES (2,002,'intel', parsedatetime('11-07-2013', 'dd-MM-yyyy'), false, 1);
INSERT INTO device (id, UID, vendor, created, status, gateway_id) VALUES (3,003,'sony', parsedatetime('01-01-2015', 'dd-MM-yyyy'),true, 1);
INSERT INTO device (id, UID, vendor, created, status, gateway_id) VALUES (4,004,'sony', parsedatetime('17-09-2012', 'dd-MM-yyyy'),true, 2);
INSERT INTO device (id, UID, vendor, created, status, gateway_id) VALUES (5,005,'huawei', parsedatetime('11-10-2013', 'dd-MM-yyyy'),true, 2);
INSERT INTO device (id, UID, vendor, created, status, gateway_id) VALUES (6,006,'dell', parsedatetime('04-05-2010', 'dd-MM-yyyy'),true, 2);
INSERT INTO device (id, UID, vendor, created, status, gateway_id) VALUES (7,007,'sony', parsedatetime('13-09-2020', 'dd-MM-yyyy'),false, 3);
INSERT INTO device (id, UID, vendor, created, status, gateway_id) VALUES (8,008,'dell', parsedatetime('05-09-2012', 'dd-MM-yyyy'),false, 3);
INSERT INTO device (id, UID, vendor, created, status, gateway_id) VALUES (9,009,'intel', parsedatetime('12-12-2013', 'dd-MM-yyyy'),true, 3);
INSERT INTO device (id, UID, vendor, created, status, gateway_id) VALUES (10,010,'dell', parsedatetime('17-07-2009', 'dd-MM-yyyy'),false, 3);
INSERT INTO device (id, UID, vendor, created, status, gateway_id) VALUES (11,011,'sony', parsedatetime('15-05-2015', 'dd-MM-yyyy'),true, 3);
INSERT INTO device (id, UID, vendor, created, status, gateway_id) VALUES (12,012,'toshiba', parsedatetime('09-09-2017', 'dd-MM-yyyy'),true, 3);
INSERT INTO device (id, UID, vendor, created, status, gateway_id) VALUES (13,013,'intel', parsedatetime('10-10-2018', 'dd-MM-yyyy'),true, 3);
INSERT INTO device (id, UID, vendor, created, status, gateway_id) VALUES (14,014,'dell', parsedatetime('11-11-2011', 'dd-MM-yyyy'),true, 3);
INSERT INTO device (id, UID, vendor, created, status, gateway_id) VALUES (15,015,'sony', parsedatetime('01-06-2021', 'dd-MM-yyyy'),false, 3);
INSERT INTO device (id, UID, vendor, created, status, gateway_id) VALUES (16,016,'sony', parsedatetime('17-06-2012', 'dd-MM-yyyy'),true, 3);
Pom.xml
<?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>2.5.3</version>
<relativePath /> <!-- lookup parent from repository -->
</parent>
<groupId>com.example</groupId>
<artifactId>gateways</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>gateways</name>
<description>gateways</description>
<properties>
<java.version>1.8</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>com.h2database</groupId>
<artifactId>h2</artifactId>
<scope>runtime</scope>
</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>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
<configuration>
<excludes>
<exclude>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
</exclude>
</excludes>
</configuration>
</plugin>
</plugins>
</build>
</project>
主班
@SpringBootApplication
@EnableAutoConfiguration
public class DemoApplication {
public static void main(String[] args) {
SpringApplication.run(DemoApplication.class, args);
}
}
网关.java
@Entity
@Table(name = "gateway")
@Data
@AllArgsConstructor
@NoArgsConstructor
public class Gateway {
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private Long id;
@Column(name="serial_number", unique = true)
private String serialNumber;
@Column(name="name", unique = true)
private String name;
@Column(name="address")
private String address;
@OneToMany(mappedBy = "gateway")
private List<Device> devices;
}
存储库
@Repository
public interface GatewayRepository extends JpaRepository<Gateway, Long>{
}
控制器
@CrossOrigin("*")
@RestController
@RequestMapping("/gateway")
public class GatewayController {
@Autowired
GatewayRepository gatewayRepository;
@GetMapping()
public ResponseEntity<List<Gateway>> getAllGateways() {
try {
List<Gateway> gateways = gatewayRepository.findAll();
if (gateways.isEmpty()) {
return new ResponseEntity<>(HttpStatus.NO_CONTENT);
}
return new ResponseEntity<>(gateways, HttpStatus.OK);
} catch (Exception e) {
return new ResponseEntity<>(null, HttpStatus.INTERNAL_SERVER_ERROR);
}
}
}
项目结构
解决方案
将以下内容添加到您的应用程序属性中,以阻止 JPAgateway
在data.sql
.
spring.jpa.hibernate.ddl-auto=none
顺便说一句,这是你唯一需要的东西application.properties
,因为其余的都是默认的。
推荐阅读
- python - 如何告诉 Seaborn/Matplotlib 在 X 轴上显示“你得到了什么”并且不要假设我希望刻度在数字上均匀分布
- javascript - 为什么这个 if 语句以非布尔值成功?
- wordpress - 我需要在 wordpress 网站上将外部链接显示为弹出窗口
- java - 如何修复我的代码以提供正确的输出而不是什么都不提供?
- azure-cosmosdb - 引导子串碰撞概率?
- python-3.x - 尝试根据 csv 文件检查用户输入
- android - 等待 Google 在 AsyncTask 中放置照片请求
- sql - Oracle SQL Developer:选择 TableName、FieldName,其中 FieldValue 为“x”
- php - “PHP Suspected”错误/黑客...如何在不丢失任何内容的情况下重新设置?
- regex - Powershell替换多个文件中的引用文本