Hibernate Error, SQLGrammarException的原因是什么

Question

我只是尝试从 Heroku 中托管的应用程序发布和获取数据。但是我得到了这个错误，

This application has no explicit mapping for /error, so you are seeing this as a fallback.
Thu May 21 11:27:53 UTC 2020
There was an unexpected error (type=Internal Server Error, status=500).
could not extract ResultSet; SQL [n/a]; nested exception is org.hibernate.exception.SQLGrammarException: could not extract ResultSet

我在我的本地主机上使用链接 Heroku Postgresql 数据库对此进行了测试，并且没有出现任何错误，并且在 post 和 get 都成功提交。上述错误仅在尝试通过 Heroku 地址获取或发布数据时发生。

以下是代码段，

实体类

import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
import org.springframework.data.annotation.CreatedDate;
import org.springframework.data.annotation.LastModifiedDate;
import org.springframework.data.jpa.domain.support.AuditingEntityListener;

import javax.persistence.*;
import javax.validation.constraints.NotBlank;
import java.util.Date;

@Entity
@Table(name = "notes")
@EntityListeners(AuditingEntityListener.class)
@JsonIgnoreProperties(value = {"createdAt", "updatedAt"},
        allowGetters = true)
public class Note {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;

    @NotBlank
    private String title;

    @NotBlank
    private String content;

    @Column(nullable = false, updatable = false)
    @Temporal(TemporalType.TIMESTAMP)
    @CreatedDate
    private Date createdAt;

    @Column(nullable = false)
    @Temporal(TemporalType.TIMESTAMP)
    @LastModifiedDate
    private Date updatedAt;

    public Long getId() {
        return id;
    }

    public void setId(Long id) {
        this.id = id;
    }

    public String getTitle() {
        return title;
    }

    public void setTitle(String title) {
        this.title = title;
    }

    public String getContent() {
        return content;
    }

    public void setContent(String content) {
        this.content = content;
    }

    public Date getCreatedAt() {
        return createdAt;
    }

    public void setCreatedAt(Date createdAt) {
        this.createdAt = createdAt;
    }

    public Date getUpdatedAt() {
        return updatedAt;
    }

    public void setUpdatedAt(Date updatedAt) {
        this.updatedAt = updatedAt;
    }

}

控制器类

import com.mcq.webapp.exception.ResourceNotFoundException;
import com.mcq.webapp.model.Note;
import com.mcq.webapp.repository.NoteRepository;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.*;

import javax.validation.Valid;
import java.util.List;

@RestController
@RequestMapping("/api")
public class NoteController {

    @Autowired
    NoteRepository noteRepository;

    @GetMapping("/notes")
    public List<Note> getAllNotes() {
        return noteRepository.findAll();
    }

    @PostMapping("/notes")
    public Note createNote(@Valid @RequestBody Note note) {
        return noteRepository.save(note);
    }

    @GetMapping("/notes/{id}")
    public Note getNoteById(@PathVariable(value = "id") Long noteId) {
        return noteRepository.findById(noteId)
                .orElseThrow(() -> new ResourceNotFoundException("Note", "id", noteId));
    }

    @PutMapping("/notes/{id}")
    public Note updateNote(@PathVariable(value = "id") Long noteId,
                                           @Valid @RequestBody Note noteDetails) {

        Note note = noteRepository.findById(noteId)
                .orElseThrow(() -> new ResourceNotFoundException("Note", "id", noteId));

        note.setTitle(noteDetails.getTitle());
        note.setContent(noteDetails.getContent());

        Note updatedNote = noteRepository.save(note);
        return updatedNote;
    }

    @DeleteMapping("/notes/{id}")
    public ResponseEntity<?> deleteNote(@PathVariable(value = "id") Long noteId) {
        Note note = noteRepository.findById(noteId)
                .orElseThrow(() -> new ResourceNotFoundException("Note", "id", noteId));

        noteRepository.delete(note);

        return ResponseEntity.ok().build();
    }
}

存储库

import com.mcq.webapp.model.Note;
import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.stereotype.Repository;



@Repository
public interface NoteRepository extends JpaRepository<Note, Long> {

}

在这种情况下，同一个项目同一个数据库，只是环境不同。因此，这是什么原因。该程序在 localhost 中运行，但不在 Heroku 环境中运行。

谢谢

Answer 1

最后，我根据@Maaaatt cmets 解决了我的问题。我更新了application.properties文件如下，

 spring.jpa.hibernate.ddl-auto = create 

谢谢，:D。