Spring Boot JPA - SQLIntegrityConstraintViolationException

Question

我正在尝试使用 jpa 保存值。我得到 SQLIntegrityConstraintViolationException。

我的模型类 - (user_answers) 表：

import org.hibernate.annotations.Type
import java.io.Serializable
import java.util.*
import javax.persistence.Column
import javax.persistence.Entity
import javax.persistence.Id
import javax.persistence.Table

@Entity
@Table(name = "user_answers")
data class CustomUserAnswer (
    @Id
    @Type(type = "uuid-char")
    @Column(name = "id")
    var id: UUID = UUID.randomUUID(),
    @Column(name="answer")
    var answer: String = "",
    @Type(type = "uuid-char")
    @Column(name = "user_answer_id")
    var userAnswerId: UUID,
    @Column(name = "question_id")
    var questionId: UUID):Serializable{}

我的模型类 - (user_answer_relt)

import org.hibernate.annotations.Type
import java.util.*
import javax.persistence.*

@Entity
@Table(name = "user_answer_relt")
data class UserAnswerRelt(
        @Id
        @Type(type = "uuid-char")
        @Column(name = "id")
        var id: UUID = UUID.randomUUID(),
        @Column(name="answer_submitted_by")
        var submittedUserName : String = "",
        @Type(type = "uuid-char")
        @Column(name="user_id")
        var userId : UUID
) {}

首先我保存 User_Answer_Relt 值并获取 User_Answer_Id 然后我使用 User_Answer_Id 构建 User_Answer 类

所以，现在我正在尝试保存 User_Answer 值，那时我遇到了以下问题。

错误：

> 19:49:43.079 [http-nio-9010-exec-1] ERROR
> o.h.e.jdbc.spi.SqlExceptionHelper - Cannot add or update a child row:
> a foreign key constraint fails (`test`.`user_answers`, CONSTRAINT
> `user_question_id_fk` FOREIGN KEY (`question_id`) REFERENCES
> `questions` (`id`)) 19:49:43.129 [http-nio-9010-exec-1] ERROR
> o.a.c.c.C.[.[.[.[dispatcherServlet] - Servlet.service() for servlet
> [dispatcherServlet] in context with path [] threw exception [Request
> processing failed; nested exception is
> org.springframework.dao.DataIntegrityViolationException: could not
> execute statement; SQL [n/a]; constraint [null]; nested exception is
> org.hibernate.exception.ConstraintViolationException: could not
> execute statement] with root cause
> java.sql.SQLIntegrityConstraintViolationException: Cannot add or
> update a child row: a foreign key constraint fails
> (`test`.`user_answers`, CONSTRAINT `user_question_id_fk` FOREIGN KEY
> (`question_id`) REFERENCES `questions` (`id`))

我知道如果 Question_Id 在问题表中不可用意味着它会引发上述异常，但我仔细检查了数据是否正确。但我不知道确切的原因。

我也尝试了模型中的加入列，但我仍然遇到同样的问题

import org.hibernate.annotations.Type
import java.util.*
import javax.persistence.*

@Entity
@Table(name = "user_answers")
data class UserAnswer(
        @Id
        @Type(type = "uuid-char")
        @Column(name = "id")
        var id: UUID = UUID.randomUUID(),
        @Column(name="answer")
        var answer: String = "",
        @Type(type = "uuid-char")
        @Column(name = "user_answer_id")
        var userAnswerId: UUID,
        @Column(name = "question_id")
        var questionId:UUID,
        @ManyToOne(fetch = FetchType.LAZY,cascade = arrayOf(CascadeType.ALL))
        @JoinColumn(name = "question_id",insertable = false,updatable = false)
        var question: Question?

){}

Answer 1

您的实体没有反映彼此之间的关系。

Hibernate 将按照不一定反映代码顺序的顺序刷新更改，但如果它知道事物之间的关系，它可以以安全的顺序发送更改。

CustomerUserAnswer 应该具有 UserAnswerRelt 和 Question 类型的属性，而不是 UUID，并且您将需要 @JoinColumn 注释。

Answer 2

我终于找到了真正的问题。

import org.hibernate.annotations.Type
import java.io.Serializable
import java.util.*
import javax.persistence.Column
import javax.persistence.Entity
import javax.persistence.Id
import javax.persistence.Table

@Entity
@Table(name = "user_answers")
data class CustomUserAnswer (
    @Id
    @Type(type = "uuid-char")
    @Column(name = "id")
    var id: UUID = UUID.randomUUID(),
    @Column(name="answer")
    var answer: String = "",
    @Type(type = "uuid-char")
    @Column(name = "user_answer_id")
    var userAnswerId: UUID,
    @Column(name = "question_id")
    var questionId: UUID):Serializable{}

在上面的代码中，我忘记添加 Column 内部类型我通过添加以下代码进行了修复。

     @Type(type = "uuid-char")
     @Column(name = "question_id")
     var questionId: UUID