为什么JPA选择查询执行会返回带有“canot execute query”消息的异常？

数据库中的表（Oracle 11g）是这样的：

名称：LOG_ALIM_MAIL

列：ID_LOG RAW（由触发器中的SYS_GUID（）自动生成），ALIMENTATION Number（9），DATE_LOG Date

PK：ID_LOG

FK：ALIMENTATION参考ALIMENTATION.ID_ALIMENTATION（Number（9））

LOG_ALIM_MAIL类：

@Entity
public class LogAlimMail implements Serializable {

private static final long serialVersionUID = 2243374060845658640L;

@Id
private Long idLog;

private Date dateLog;

private Alimentation alimentation;

public LogAlimMail() {

}

public Long getIdLog() {
    return idLog;
}

public void setIdLog(Long idLog) {
    this.idLog = idLog;
}

public Date getDateLog() {
    return dateLog;
}

public void setDateLog(Date dateLog) {
    this.dateLog = dateLog;
}

@ManyToOne(cascade = { CascadeType.PERSIST, CascadeType.MERGE })
public Alimentation getAlimentation() {
    return alimentation;
}

public void setAlimentation(Alimentation alimentation) {
    this.alimentation = alimentation;
}
}

营养类：@Entity public class Alimentation实现Serializable {

private static final long serialVersionUID = 5790314265385194058L;

private Long idAlimentation;

private Integer etat;

public Alimentation() {

}

@Id
@GeneratedValue(strategy = GenerationType.AUTO, generator = "my_alimentation_seq_gen")
@SequenceGenerator(name = "my_alimentation_seq_gen", sequenceName = "SEQ_ID_ALIMENTATION")
public Long getIdAlimentation() {
    return idAlimentation;
}

public Integer getEtat() {
    return etat;
}

public void setEtat(Integer etat) {
    this.etat = etat;
}

public void setIdAlimentation(Long idAlimentation) {
    this.idAlimentation = idAlimentation;
}
}

我有两个问题：

• 我正在尝试执行以下选择查询：

public List<LogAlimMail> getAllByIdAlim(Long idAlim) {
String request = "select a from LogAlimMail a where a.alimentation.idAlimentation = " + idAlim;

Query query = this.getEntityManager().createQuery(request);

return query.getResultList();
}

我得到了例外：

java.lang.IllegalArgumentException: org.hibernate.QueryException: could not resolve property: idAlimentation of: administration.LogAlimMail [select a from administration.LogAlimMail a where a.alimentation.idAlimentation = 1]

• 我无法在idLog（Long）和ID_LOG（由SYS_GUID（）生成的RAW）之间进行正确的JPA映射 .

谢谢