JPA 中的参照完整性约束违反错误

Posted 2023-02-26

【中文标题】JPA 中的参照完整性约束违反错误

【英文标题】：Referential integrity constraint violation error in JPA

【发布时间】：2017-12-25 20:03:45

【问题描述】：

我正在尝试解析 Web 请求并保存到数据库。我有 3 个模型，第一个节点是 virtualDocument。这是 uniq 表（根据请求 url）。 VirtualRequest 表具有所有 erquest 主体，而 HttpHeaderList 表根据其 virtualRequest bean id 具有所有 thhp 标头。

当我尝试保存我得到的第一个日志时，出现这样的错误；

org.h2.jdbc.JdbcSQLException: Referential integrity constraint violation: "FK1TW2G47F7A47580KQVMDJWGBQ: PUBLIC.T_VIRTUAL_REQUEST FOREIGN KEY(REQUEST_ID) REFERENCES PUBLIC.T_VIRTUAL_DOCUMENT(DOCUMENT_ID) (65)"; SQL statement:
insert into t_virtual_request (request_id, media_type, method_type, request_url) values (null, ?, ?, ?) [23506-192]
    at org.h2.message.DbException.getJdbcSQLException(DbException.java:345) ~[h2-1.4.192.jar:1.4.192]

这里是 VirtualDocument bean

@Entity
@Table(name = "t_virtual_document")
public class VirtualDocument 

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Column(name = "document_id")
    private long documentId;

    @Column(name = "real_url", unique = true)
    private String realURL; //uniq

    @Column(name = "virtual_url", unique = true)
    private String virtualURL; //uniq

    @Column(name = "simulation_mode", columnDefinition = "varchar(10) default 'STOP'")
    private String simulationMode;

    @OneToMany(cascade = CascadeType.ALL)
    @JoinColumn(name = "request_id")
    private List<VirtualRequest> requestList;

    @OneToMany(cascade = CascadeType.ALL)
    @JoinColumn(name = "response_id")
    private List<VirtualResponse> responseList;

   //getter setter without any annotation

这里是 VirtualRequest bean；

@Entity
@Table(name = "t_virtual_request")
public class VirtualRequest 

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Column(name = "request_id")
    private long requestId;

    @Column(name = "request_url")
    private String requestURL;

    @Column(name = "method_type")
    private String methodType;

    @Column(name = "media_type")
    private String mediaType;

    @OneToMany(cascade = CascadeType.ALL)
    @JoinColumn(name = "header_id")
    private List<HttpHeaderList> requestHeaders;

   //getter setter without any annotation

这里是 HeaderList bean；

@Entity
@Table(name = "t_http_headers")
public class HttpHeaderList 

    @Id
    @Column(name = "header_id")
    private long headerId;

    @Column(name = "header_key")
    private String headerKey;

    @Column(name = "header_value")
    private String headerValue;

【问题讨论】：

看起来你的 JPA 映射不正确。如果您希望每个 VirtualDocument 有多个请求，则需要从 VirtualRequest 到文档的外键。然后，您将在 @OneToMany 注释中使用 mappedBy 参数将点 JPA 告知外键属性。

mappedBy 参数可以是东西还是必须是字段？

请看我的回答。通过点映射到拥有关系的实体中的字段。

【参考方案1】：

我认为这是你想要的：

@Entity
@Table(name = "t_virtual_document")
public class VirtualDocument 

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Column(name = "document_id")
    private long documentId;

    @Column(name = "real_url", unique = true)
    private String realURL; //uniq

    @Column(name = "virtual_url", unique = true)
    private String virtualURL; //uniq

    @Column(name = "simulation_mode", columnDefinition = "varchar(10) default 'STOP'")
    private String simulationMode;

    @OneToMany(cascade = CascadeType.ALL, mappedBy = "virtualDocument")
    private List<VirtualRequest> requestList;

    @OneToMany(cascade = CascadeType.ALL, mappedBy = "virtualDocument")
    // Note the mappedBy parameter. This points to the property in the entity that owns the relationship (in this case the VirtualResponse).
    private List<VirtualResponse> responseList;

   //getter setter without any annotation


@Entity
@Table(name = "t_virtual_request")
public class VirtualRequest 

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Column(name = "request_id")
    private long requestId;

    @ManyToOne(fetch = FetchType.LAZY)
    @JoinColumn(name = "document_id")
    private VirtualDocument virtualDocument;

    @Column(name = "request_url")
    private String requestURL;

    @Column(name = "method_type")
    private String methodType;

    @Column(name = "media_type")
    private String mediaType;

    @OneToMany(cascade = CascadeType.ALL, mappedBy = "virtualRequest")
    private List<HttpHeaderList> requestHeaders;

   //getter setter without any annotation


@Entity
@Table(name = "t_http_headers")
public class HttpHeader  /*Note this is a more appropriate name for the entity since it holds the data of a single header.*/

    @Id
    @Column(name = "header_id")
    private long headerId;

    @Column(name = "header_key")
    private String headerKey;

    @Column(name = "header_value")
    private String headerValue;

    @ManyToOne(fetch = FetchType.LAZY)
    @JoinColumn(name = "request_id")
    private VirtualRequest virtualRequest

    @ManyToOne(fetch = FetchType.LAZY)
    @JoinColumn(name = "response_id")
    private VirtualResponse virtualResponse;

更新了答案以添加将标头映射到请求实体。

【讨论】：

@ManyToOne(fetch = FetchType.LAZY) @JoinColumn(name = "document_id") private long documentId;在这个字段类型中，必须是long还是VirtualDocument？

不.. 我的错。它需要与实体类型相同。让我解决这个问题。

抱歉有问题，但是我对这些映射主题有很大的问题，最后一个问题，我的 HttpHeaderList bean 和其他请求-响应 bean 需要映射吗？如果是的话怎么办？因为我得到一个错误标记为 mappedBy 的关联不能定义像 JoinTable 或 JoinColumn 这样的数据库映射：VirtualResponse.responseHeaders

试试更新的代码。始终考虑哪个实体拥有关系（外键）。该实体具有 JoinColumn 注释。目标实体有 OneToMany 和 mappedBy 参数。

正确！您不能在同一个字段中同时拥有两者。