Mappedsuperclass和namedqueries

Question

我有這樣的mappedsuperclass：

@MappedSuperclass 
@DiscriminatorColumn(name = "USER_TYPE") 
@Inheritance(strategy = InheritanceType.SINGLE_TABLE) 
@NamedQueries({ 
     @NamedQuery(name = "selectAllUsers", query = "SELECT u FROM User u"), 
     @NamedQuery(name = "deleteUserByName", query = "DELETE FROM User u WHERE u.userName like :name"), 
     @NamedQuery(name = "getUserByName", query = "SELECT FROM User u WHERE u.userName like :name") }) 
public abstract class User implements Serializable {.... 

我得到「的抽象模式類型 '用戶' 未知」 的namedquery錯誤。我不明白爲什麼...用戶名是正確的？

任何建議將受到歡迎。

Answer 1

這是預期的JPA行爲。映射超類不可查詢（請參閱JPA 2.0規範，部分 2.11.2）。如果要製作超類可查詢，請將註釋從@MappedSuperclass更改爲@Entity。