Java JPQL（EclipseJPAProcider）无法对int调用方法

因此，我在Netbean JPQL工具中使用了以下JPQL

SELECT e.idEtu, e.nomEtu, e.prenomEtu,e.ddnEtu 
FROM Etudiant e,InscrireClasse i, Niveau n 
WHERE i.idNiveau = n.idNiveau  AND n.nomNiveau='Master 1'

当我运行它时，我不知道为什么，但是有一个Bug。下面是JPA日志（它说不能在int上调用方法…不知道它是什么意思）

如果我在没有I.idNiveau=n.idNiveau的情况下运行它，它工作得非常好

javax.persistence.PersistenceException: Exception [EclipseLink-4002]    (Eclipse Persistence Services - 2.5.2.v20140319-9ad6abd):    org.eclipse.persistence.exceptions.DatabaseException
Internal Exception: com.microsoft.sqlserver.jdbc.SQLServerException:     Cannot call methods on int.
Error Code: 258
Call: SELECT t0.id_etu, t0.nom_etu, t0.prenom_etu, t0.ddn_etu FROM     GESTION_DES_NOTES.dbo.etudiant t0, GESTION_DES_NOTES.dbo.niveau t2, GESTION_DES_NOTES.dbo.InscrireClasse t1 WHERE ((t1.id_niveau = t2.id_niveau.t2.id_niveau) AND (t2.nom_niveau = ?))
bind => [1 parameter bound]
Query: ReportQuery(referenceClass=Etudiant sql="SELECT t0.id_etu,  t0.nom_etu, t0.prenom_etu, t0.ddn_etu FROM GESTION_DES_NOTES.dbo.etudiant t0, GESTION_DES_NOTES.dbo.niveau t2, GESTION_DES_NOTES.dbo.InscrireClasse t1 WHERE ((t1.id_niveau = t2.id_niveau.t2.id_niveau) AND (t2.nom_niveau = ?))")
at org.eclipse.persistence.internal.jpa.QueryImpl.getDetailedException(QueryImpl.java:378)
at org.eclipse.persistence.internal.jpa.QueryImpl.executeReadQuery(QueryImpl.java:260)
at org.eclipse.persistence.internal.jpa.QueryImpl.getResultList(QueryImpl.java:469)
Caused by: Exception [EclipseLink-4002] (Eclipse Persistence Services - 2.5.2.v20140319-9ad6abd): org.eclipse.persistence.exceptions.DatabaseException
Internal Exception: com.microsoft.sqlserver.jdbc.SQLServerException:        Cannot call methods on int.
    Error Code: 258
Call: SELECT t0.id_etu, t0.nom_etu, t0.prenom_etu, t0.ddn_etu FROM GESTION_DES_NOTES.dbo.etudiant t0, GESTION_DES_NOTES.dbo.niveau t2, GESTION_DES_NOTES.dbo.InscrireClasse t1 WHERE ((t1.id_niveau = t2.id_niveau.t2.id_niveau) AND (t2.nom_niveau = ?))
bind => [1 parameter bound]
Query: ReportQuery(referenceClass=Etudiant sql="SELECT t0.id_etu, t0.nom_etu, t0.prenom_etu, t0.ddn_etu FROM GESTION_DES_NOTES.dbo.etudiant t0, GESTION_DES_NOTES.dbo.niveau t2, GESTION_DES_NOTES.dbo.InscrireClasse t1 WHERE ((t1.id_niveau = t2.id_niveau.t2.id_niveau) AND (t2.nom_niveau = ?))")
at org.eclipse.persistence.exceptions.DatabaseException.sqlException(DatabaseException.java:340)
at org.eclipse.persistence.internal.databaseaccess.DatabaseAccessor.basicExecuteCall(DatabaseAccessor.java:682)
...

如果我试着转换位置写n.idNiveau=I.idNiveau而不是I.idNiveau=n.idNiveau

Local Exception Stack: 
Exception [EclipseLink-6076] (Eclipse Persistence Services - 2.5.2.v20140319-9ad6abd): org.eclipse.persistence.exceptions.QueryException
Exception Description: Object comparisons can only be used with    OneToOneMappings.  Other mapping comparisons must be done through query keys or direct attribute level comparisons. 
Mapping:   [org.eclipse.persistence.mappings.DirectToFieldMapping[idNiveau-->GESTION_DES_NOTES.dbo.niveau.id_niveau]] 
Expression: [
Query Key idNiveau
 Base Entity_classes.Niveau]
Query: ReportQuery(referenceClass=Etudiant jpql="SELECT e.idEtu, e.nomEtu, e.prenomEtu,e.ddnEtu 

来自美国纽约州尼维尔市一级研究生教育学院

---

其中，n.idNiveau=i.idNiveau和n.nomNiveau='Master 1'）

您是否有一个属性

inscrirecase.niveau

？@wero Nope.在inscrirecase类中，我有一个属性idNiveau_uuuu'，而niveau是另一个属性为idNiveau和nom_niveau的类。（idNiveau是Niveau中的主键，INSCRIRIRECLASSE中的引用键或外键）没有这些类，谁能对此发表评论？@NeilStockton Ouch我很失望，删除了这个项目。我自己找不到任何东西。