Question

我有Accommodation和Booking类之间的关系，我也在预订表中设置了一个外键。

ALTER TABLE `project`.`booking` 
ADD INDEX `fk_accId_fk_idx` (`accommodation` ASC);
ALTER TABLE `project`.`booking` 
ADD CONSTRAINT `fk_accId_fk`
  FOREIGN KEY (`accommodation`)
  REFERENCES `project`.`accommodation` (`id`)
  ON DELETE NO ACTION
  ON UPDATE NO ACTION;

住宿等级：

@Entity
  ....
public class Accommodation implements Serializable {
  @Id
  @GeneratedValue(strategy = GenerationType.IDENTITY)
  @Column(name = "id", unique = true, nullable = false)
  private BigInteger id;

  @OneToMany(mappedBy = "accommodation", fetch = FetchType.EAGER, cascade = CascadeType.REMOVE)
  @JsonManagedReference
  private List < Booking > bookings;
  ......getters setters
}

预订课程：

@Entity
public class Booking implements Serializable {
  ......
  @ManyToOne(fetch = FetchType.EAGER)
  @JoinColumn(name = "bookings", nullable = true)
  @JsonBackReference
  private Accommodation accommodation;
  ....getters setters
}

当我执行列表调整的查询时，我在字段列表错误中得到未知列。

javax.persistence.PersistenceException：org.hibernate.exception.SQLGrammarException：无法从根提示中提取ResultSet com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException：未知列＆＃39; bookings7_.bookings＆＃39;在＆＃39;字段列表＆＃39;

即使我设置关系并在表中定义外键，我得到此错误的原因是什么？

Answer 1

尝试在JPA中手动定义连接表映射。删除架构并让JPA创建表：

住宿等级

@OneToMany(mappedBy = "accommodation", fetch = FetchType.EAGER, cascade = CascadeType.REMOVE)
@JsonManagedReference
private List < Booking > bookings;

预订课程

@ManyToOne(fetch = FetchType.EAGER)
@JoinTable(name = "accommodation_booking_join_table", 
           joinColumns = {@JoinColumn(name="booking_id")},
           inverseJoinColumns = @JoinColumn(name = "accommodation_id"))
@JsonBackReference
private Accommodation accommodation;

Answer 2

尝试在db和entity类中将列名更改为小写。

Answer 3

我有这种情况，我通过更改字段在查询上的位置来解决它。看起来它是一个MySQL错误，就像这篇文章中提到的那个（或相同）：

https://bugs.mysql.com/bug.php?id=1689

这个MySQL错误的描述提到了一个类似的解决方案：“我发现通过交换该字段在表中的位置与另一个字段工作正常。”

字段列表中的JPA未知列

3 个答案: