Question

希望有人可以启发我;这是我第一次涉足JPA，我试图基于Oracle SQL查询对实体关系进行反向工程。这是查询：

select n.incoming, n.outgoing, c.claim_id, c.claim_label, c.claim_date, c.claim_status
from CLAIM c
    left join PERSON p on p.person_id = c.person_id
      left join NMI_VIEW n on n.claim_id = c.claim_id
            and n.person_identifier = p.person_identifier
;

基本上，PERSON表在此查询中充当中间表，但不保证在c.person_id列上具有匹配项。我只想从NMI_VIEW视图中获取一行，如果它与claim_id和person_identifier匹配。因此NMI_VIEW联接基于2个不同表中的2列。

所以我的问题是，是否有可能（以及如何）让JPA投影/实体产生这种类型的查询？我将列出我在下面的当前课程的基本部分。

NmiViewPK

public class NmiViewPK implements Serializable {
    private Long claimId;
    private String personIdentifier;
}

NmiViewProjection：

@Data
@Immutable
@Entity
@IdClass(NmiViewPK.class)
@Table(name = "NMI_VIEW")
public class NmiViewEntity {
    @Id
    @Column(name = "CLAIM_ID")
    private Long claimId;

    @Id
    @Column(name="PERSON_IDENTIFIER")
    private String personIdentifier;

    // ??? This is either a 1 or 0; can I make it a Boolean instead of Integer??
    @Column(name = "OUTGOING")
    private Integer outgoing;

    // ??? This is either a 1 or 0; can I make it a Boolean instead of Integer??
    @Column(name = "INCOMING")
    private Integer incoming;

    @Column(name = "SINGLE_STATUS")
    private Integer singleStatus;
}

PersonProjection：

@Data
@Entity
@Immutable
@EqualsAndHashCode(of = "personId")
@ToString(of = "personId")
@Table(name = "PERSON")
public class PersonProjection {

    public PersonProjection() {
        // JPA
    }

    @Id
    @Column(name = "PERSON_ID")
    private Long personId;

    @Column(name = "PERSON_IDENTIFIER")
    private String personIdentifier;

    @Column(name = "FIRST_NAME")
    private String firstName;

    @Column(name = "MIDDLE_NAME")
    private String middleName;

    @Column(name = "LAST_NAME")
    private String lastName;

    @Column(name = "SSN")
    private String ssn;

    @Column(name = "DATE_OF_BIRTH")
    private Date dateOfBirth;

}

ClaimProjection：

@NamedEntityGraph(name = "ClaimProjection.graph",
        attributeNodes = {
                @NamedAttributeNode(value = "personProjection"),
                @NamedAttributeNode(value = "nmiViewEntity")})
@Data
@Entity
@Immutable
@EqualsAndHashCode(of = "claimId")
@ToString(of = "claimId")
@Table(name = "CLAIM")
public class ClaimProjection {

    public ClaimProjection() {
        // JPA
    }

    @Id
    @Column(name = "CLAIM_ID")
    private Long claimId;

    @Column(name = "CLAIM_LABEL")
    private String claimLabel;

    @Column(name = "CLAIM_DATE")
    @Temporal(TemporalType.TIMESTAMP)
    private Date claimDate;

    @Column(name = "CLAIM_STATUS")
    private String claimStatus;

    @OneToOne(fetch = FetchType.LAZY)
    @JoinColumn(name = "PERSON_ID")
    @NotFound(action = NotFoundAction.IGNORE)
    private PersonProjection personProjection;

    // TODO Do not know how to properly join NMI_VIEW here!!
    @OneToOne(fetch = FetchType.Lazy)
    @LazyToOne(LazyToOneOption.NO_PROXY)
    @JoinColumns({
        @JoinColumn(name = "CLAIM_ID", insertable = false, updatable = false),
        @JoinColumn(name = "PersonProjection.PERSON_IDENTIFIER", insertable = false, updatable = false)
    })
    @NotFound(action = NotFoundAction.IGNORE)
    private NmiViewEntity nmiViewEntity;

}

我继承了这段代码，并在ClaimProjection.nmiViewEntity上添加了一些注释作为如何执行连接的最佳猜测，但~~我感觉它们无法正常工作。~~如果任何人对如何正确连接有任何想法，也许对此处的任何其他更正，我真的很感激！提前谢谢！

编辑1：我按原样测试了这些类，但它目前无效，部分原因是NmiViewEntity上没有合适的复合ID。（不确定我是否应该在这里使用复合ID类或嵌入式ID类？）

编辑2：为NmiViewEntity添加了PK类。添加复合ID类后，我收到此错误：

2017-07-05 16:06:57.316 ERROR 12279 --- [main]
o.h.engine.jdbc.spi.SqlExceptionHelper   : ORA-00904: "CLAIMPR0_"."PERSON_PROJECTION_PERSON_IDENTIFIER": invalid identifier

JPA / Hibernate：如何使用来自2个表/实体（一个左连接）的列对视图/实体进行一对一连接？

0 个答案: