springboot怎么和mysql连接
时间: 2023-09-18 22:16:22 浏览: 31
要使用Spring Boot连接MySQL数据库,必须遵循以下步骤:
1. 在pom.xml文件中添加MySQL的依赖项:
```
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
</dependency>
```
2. 在application.properties文件中配置数据库连接信息:
```
spring.datasource.url=jdbc:mysql://localhost:3306/db_name
spring.datasource.username=username
spring.datasource.password=password
spring.datasource.driver-class-name=com.mysql.jdbc.Driver
```
3. 创建一个实体类,该类的属性应该与数据库表的列名相匹配,并使用@Entity和@Table注释:
```
@Entity
@Table(name = "users")
public class User {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
private String name;
private String email;
// getters and setters
}
```
4. 创建一个接口继承JpaRepository接口,用于与数据库进行交互:
```
@Repository
public interface UserRepository extends JpaRepository<User, Long> {
}
```
5. 在应用程序主类上添加@EnableJpaRepositories注释,以启用Spring Data JPA自动配置:
```
@SpringBootApplication
@EnableJpaRepositories
public class MyApp {
public static void main(String[] args) {
SpringApplication.run(MyApp.class, args);
}
}
```
6. 现在可以在应用程序中使用UserRepository来访问数据库:
```
@Service
public class UserService {
private final UserRepository userRepository;
public UserService(UserRepository userRepository) {
this.userRepository = userRepository;
}
public User getUser(Long id) {
return userRepository.findById(id).orElseThrow(() ->
new NotFoundException("User not found with id " + id));
}
public User createUser(User user) {
return userRepository.save(user);
}
public void deleteUser(Long id) {
userRepository.deleteById(id);
}
}
```
以上就是使用Spring Boot连接MySQL数据库的基本步骤。