Question

当我使用外键搜索实体及其记录时遇到问题。按照业务逻辑，我需要搜索Entity-LookupRequest表，该帐户具有帐户（帐户ID不为null）和外键=“ callback”（具有null）。

请注意，帐户ID不是唯一的（为简单起见，我删除了表中的其他参数以使其简短）。过滤记录后，必须将LookupRequest.callBack更新为Foreignkey条目。当外键为空时，我无法检索记录。

import javax.persistence.*;

@Entity
public class LookupRequest {

    @Id
    @GeneratedValue(strategy= GenerationType.AUTO)
    private Long id;

    @Column
    private String account;

    @Column
    private String caseId;

    @OneToOne(cascade = CascadeType.ALL, fetch = FetchType.LAZY, optional = true)
    @JoinColumn(name = "id", unique=false, nullable=true, updatable=true)
    private Callback callback;

    public LookupRequest(String account, String caseId) {
        this.account = account;
        this.caseId = caseId;
        callback = null;
    }

    public Long getId() {
        return id;
    }

    public String getAccount() {
        return account;
    }

    public String getCaseId() {
        return caseId;
    }

    public Callback getCallback() {
        return callback;
    }

    public void setCallback(Callback callback) {
        this.callback = callback;
    }

}


@Repository
public interface LookupRequestRepository extends JpaRepository<LookupRequest, Long> {
    @Query("SELECT lr from LookupRequest lr where lr.account = :account and lr.callback = :callback")
    LookupRequest findCaseId(@Param("account") String account, @Param("callback") String callback);
}    


@Getter
@Setter
@Entity
public class Callback {

    @Id
    @GeneratedValue(strategy= GenerationType.AUTO)
    public Long id;

    @Column(length = 20000)
    private String rawResponse;

    public Long getId() {
        return id;
    }

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

    public void setRawResponse(String rawResponse) {
        this.rawResponse = rawResponse;
    }

}

然后我打电话如下：

LookupRequest lookupRequestFromDB = lookupRequestRepository.findCaseId("ABC", null);

出了什么问题？

Answer 1

NULL不等于任何东西，您需要使用“ is NULL”。参见here

在您的情况下：

SELECT lr from LookupRequest lr where lr.account = :account and (lr.callback = :callback or lr.callback is null)

当外键为空时，无法使用Spring Data JPA存储库检索记录

1 个答案: