試圖堅持多對一實體時，我得到一個錯誤：違反外鍵約束堅持時多到一個
Internal Exception: org.postgresql.util.PSQLException: ERROR: insert or update on table "concept" violates foreign key constraint "concept_concept_class_fk" Detail: Key (concept_class_id)=(Concept) is not present in table "concept_class". Error Code: 0 Call: INSERT INTO concept (concept_key, description, label, code, concept_class_id) VALUES (?, ?, ?, ?, ?) bind => [27, description_1, label_1, code_1, Concept] Query: InsertObjectQuery(com.mirth.results.entities.Concept[conceptKey=27]) at com.sun.ejb.containers.BaseContainer.checkExceptionClientTx(BaseContainer.java:3728) at com.sun.ejb.containers.BaseContainer.postInvokeTx(BaseContainer.java:3576) at com.sun.ejb.containers.BaseContainer.postInvoke(BaseContainer.java:1354) ... 101 more
這是一種嘗試堅持它的方法。我已經把一個註釋，其中行是：
@Override
public void loadConcept(String metaDataFilePath, String dataFilePath) throws Exception {
try {
ConceptClassMetaData conceptClassMetaData = (ConceptClassMetaData) ModelSerializer.getInstance().fromXML(FileUtils.readFileToString(new File(metaDataFilePath), "UTF8"));
em.executeNativeQuery(conceptClassMetaData.getCreateStatement());
ConceptClassRow conceptClassRow = conceptClassMetaData.getConceptClassRow();
ConceptClass conceptClass = em.findByPrimaryKey(ConceptClass.class, conceptClassRow.getId());
if (conceptClass == null) {
conceptClass = new ConceptClass(conceptClassRow.getId());
}
conceptClass.setLabel(conceptClassRow.getLabel());
conceptClass.setOid(conceptClassRow.getOid());
conceptClass.setDescription(conceptClassRow.getDescription());
conceptClass = em.merge(conceptClass);
DataParser dataParser = new DataParser(conceptClassMetaData, dataFilePath);
for (ConceptModel conceptModel : dataParser.getConceptRows()) {
ConceptFilter<Concept> filter = new ConceptFilter<Concept>(Concept.class);
filter.setCode(conceptModel.getCode());
filter.setConceptClass(conceptClass.getLabel());
List<Concept> concepts = em.findAllByFilter(filter);
Concept concept = new Concept();
if (concepts != null && !concepts.isEmpty()) {
concept = concepts.get(0);
}
concept.setCode(conceptModel.getCode());
concept.setDescription(conceptModel.getDescription());
concept.setLabel(conceptModel.getLabel());
concept.setConceptClass(conceptClass);
concept = em.merge(concept); //THIS LINE CAUSES THE ERROR!
}
} catch (Exception e) {
e.printStackTrace();
throw e;
}
}
...
下面是如何在兩個實體的定義：
@Entity
@Table(name = "concept")
@Inheritance(strategy=InheritanceType.JOINED)
@DiscriminatorColumn(name="concept_class_id", discriminatorType=DiscriminatorType.STRING)
public class Concept extends KanaEntity {
@Id
@Basic(optional = false)
@Column(name = "concept_key")
protected Integer conceptKey;
@Basic(optional = false)
@Column(name = "code")
private String code;
@Basic(optional = false)
@Column(name = "label")
private String label;
@Column(name = "description")
private String description;
@JoinColumn(name = "concept_class_id", referencedColumnName = "id")
@ManyToOne
private ConceptClass conceptClass;
...
@Entity
@Table(name = "concept_class")
public class ConceptClass extends KanaEntity {
@Id
@Basic(optional = false)
@Column(name = "id")
private String id;
@Basic(optional = false)
@Column(name = "label")
private String label;
@Column(name = "oid")
private String oid;
@Column(name = "description")
private String description;
....
而且也，重要的是這是在SQL正在生成：
INSERT INTO concept_class (id, oid, description, label) VALUES (?, ?, ?, ?) bind => [LOINC_TEST, 2.16.212.31.231.54, This is a meta data file for LOINC_TEST, loinc_test]
INSERT INTO concept (concept_key, description, label, code, concept_class_id) VALUES (?, ?, ?, ?, ?) bind => [27, description_1, label_1, code_1, Concept]
這是失敗的原因很明顯：它插入單詞Concept_class_id的概念。它應該插入單詞LOINC_TEST。我無法弄清楚它爲什麼使用這個詞。我使用調試器來查看Concept和ConceptClass實例，它們都不包含這個詞。我正在使用eclipselink。有誰知道爲什麼會發生這種情況？