spring boot错误：spring表不存在

Question

当我试图在数据库中保存角色时，会出现“springit.role表不存在”。

我没有在我的数据库中创建一个名为“role”的表，因为我正在学习的课程中的老师没有创建一个表。

在DatabaseLoader类方法中调用“AddUserSandRoles（）”时显示的异常

那么，问题出在哪里呢？

role.java

@Entity
@RequiredArgsConstructor
@Getter
@Setter
@ToString
@NoArgsConstructor
public class Role {
    @Id
    @GeneratedValue
    private Long id;

    @NonNull
    private String name;

    @ManyToMany( mappedBy = "roles")
    private Collection<User> users;

}

user.java

@Entity
@RequiredArgsConstructor
@Getter
@Setter
@ToString
@NoArgsConstructor
public class User implements UserDetails {
    @Id @GeneratedValue
    private Long id;

    @NonNull
    @Size(min = 8, max = 20)
    @Column(nullable = false, unique = true)
    private String email;

    @NonNull
    @Column(length = 100)
    private String password;

    @NonNull
    @Column(nullable = false)
    private boolean enabled;

    @ManyToMany(fetch = FetchType.EAGER)
    @JoinTable(
            name = "users_roles",
            joinColumns = @JoinColumn(name = "user_id",referencedColumnName = "id"),
            inverseJoinColumns = @JoinColumn(name = "role_id",referencedColumnName = "id")
    )
    private Set<Role> roles = new HashSet<>();

    public void addRole(Role role) {
        roles.add(role);
    }

    public void addRoles(Set<Role> roles) {
        roles.forEach(this::addRole);
    }


    @Override
    public Collection<? extends GrantedAuthority> getAuthorities() {
        return roles.stream().map(role -> new SimpleGrantedAuthority(role.getName())).collect(Collectors.toList());
    }


    @Override
    public String getUsername() {
        return email;
    }

    @Override
    public boolean isAccountNonExpired() {
        return true;
    }

    @Override
    public boolean isAccountNonLocked() {
        return true;
    }

    @Override
    public boolean isCredentialsNonExpired() {
        return true;
    }

    @Override
    public boolean isEnabled() {
        return enabled;
    }
}

DatabaseLoader.java

@Component
public class DatabaseLoader implements CommandLineRunner {

    private LinkRepository linkRepository;
    private CommentRepository commentRepository;
    private RoleRepository roleRepository;
    private UserRepository userRepository;

    public DatabaseLoader(LinkRepository linkRepository, CommentRepository commentRepository, RoleRepository roleRepository, UserRepository userRepository) {
        this.linkRepository = linkRepository;
        this.commentRepository = commentRepository;
        this.roleRepository = roleRepository;
        this.userRepository = userRepository;
    }

    @Override
    public void run(String... args) {

        addUsersAndRoles();

        Map<String,String> links = new HashMap<>();
        links.put("Securing Spring Boot APIs and SPAs with OAuth 2.0","https://auth0.com/blog/securing-spring-boot-apis-and-spas-with-oauth2/?utm_source=reddit&utm_medium=sc&utm_campaign=springboot_spa_securing");
        links.put("Easy way to detect Device in Java Web Application using Spring Mobile - Source code to download from GitHub","https://www.opencodez.com/java/device-detection-using-spring-mobile.htm");
        links.put("Tutorial series about building microservices with SpringBoot (with Netflix OSS)","https://medium.com/@marcus.eisele/implementing-a-microservice-architecture-with-spring-boot-intro-cdb6ad16806c");

        links.forEach((k,v) -> {
            linkRepository.save(new Link(k,v));
            // we will do something with comments later
        });

        long linkCount = linkRepository.count();
        System.out.println("Number of links in the database: " + linkCount );
    }

      private void addUsersAndRoles() {
        BCryptPasswordEncoder encoder = new BCryptPasswordEncoder();
        String secret = "{bcrypt}" + encoder.encode("password");

        Role userRole = new Role("ROLE_USER");
        roleRepository.save(userRole);
        Role adminRole = new Role("ROLE_ADMIN");
        roleRepository.save(adminRole);

        User user = new User("[e-mail]",secret,true);
        user.addRole(userRole);
        userRepository.save(user);

        User admin = new User("[e-mail]",secret,true);
        admin.addRole(adminRole);
        userRepository.save(admin);

        User master = new User("[e-mail]",secret,true);
        master.addRoles(new HashSet<>(Arrays.asList(userRole,adminRole)));
        userRepository.save(master);

    }

}

schema.sql

 CREATE DATABASE  IF NOT EXISTS `springit`;
USE `springit`;

DROP TABLE IF EXISTS `comment`;

CREATE TABLE `comment` (
                           `id` bigint(20) NOT NULL AUTO_INCREMENT,
                           `created_by` varchar(255) DEFAULT NULL,
                           `creation_date` datetime DEFAULT NULL,
                           `last_modified_by` varchar(255) DEFAULT NULL,
                           `last_modified_date` datetime DEFAULT NULL,
                           `body` varchar(255) DEFAULT NULL,
                           `link_id` bigint(20) DEFAULT NULL,
                           PRIMARY KEY (`id`),
                           KEY `FKoutxw6g1ndh1t6282y0fwvami` (`link_id`)
) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci;

DROP TABLE IF EXISTS `link`;
CREATE TABLE `link` (
                        `id` bigint(20) NOT NULL AUTO_INCREMENT,
                        `created_by` varchar(255) DEFAULT NULL,
                        `creation_date` datetime DEFAULT NULL,
                        `last_modified_by` varchar(255) DEFAULT NULL,
                        `last_modified_date` datetime DEFAULT NULL,
                        `title` varchar(255) DEFAULT NULL,
                        `url` varchar(255) DEFAULT NULL,
                        PRIMARY KEY (`id`)
) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci;

我是新来springboot的，所以请帮帮我。

例外情况：

null

Answer 1

您肯定需要这个表，可以是自己创建的，也可以是Hibernate创建的。

有一个配置，您可以使用JPA添加到spring boot应用程序中，以便自动生成数据库模式（或缺少的部分）。看看这里https://docs.spring.io/spring-boot/docs/1.1.0.m1/reference/html/howto-database-initialization.html