HQL問題

Question

嗨每一個我有這些CLASSE

@Entity 
@Table(name = "login", uniqueConstraints={@UniqueConstraint(columnNames={"username_fk"})}) 
public class Login implements Serializable { 

    @Id 
    @Column(name = "id") 
    @GeneratedValue 
    private int id; 
    @Column(name = "password", length = 64) 
    private String password; 
    @Column(name = "roles", length = 32) 
    private String roles; 
    @OneToOne(fetch = FetchType.EAGER, cascade = CascadeType.ALL) 
    @OnDelete(action=OnDeleteAction.CASCADE) 
    @Cascade(org.hibernate.annotations.CascadeType.DELETE_ORPHAN) 
    @JoinColumn(name = "username_fk", nullable=false) 
    private Branch branch; 
    //some getter and sette 

和

@Entity 
@Table(name = "branch", uniqueConstraints = {@UniqueConstraint(columnNames = {"bname", "branch_fk"})}) 
public class Branch implements Serializable { 

    @Id 
    @GeneratedValue 
    private int id; 
    @Column(name = "username", length = 64, nullable=false) 
    private String userName; 
    @Column(name = "bname", length = 64) 
    private String branchName; 
    @Column(name = "officername", length = 64) 
    private String officerName; 
    @Column(name = "studcount") 
    private int studCount; 
    @Column(name = "blevel", columnDefinition="int default 0") 
    private int level; 
    @Column(name = "officeremail", length = 64) 
    private String officerEmail; 
    @Column(name = "confirmed", columnDefinition = "tinyint default 0") 
    private int confirmed; 

    @OneToOne(mappedBy = "branch", fetch = FetchType.LAZY, cascade = CascadeType.ALL) 
    @OnDelete(action=OnDeleteAction.CASCADE) 
    @Cascade(org.hibernate.annotations.CascadeType.DELETE_ORPHAN) 
    private Login login; 

當我使用這個查詢：

executeQuery("select l from Login as l inner join l.branch as b where l.branch.bname = ?", username) 

或本：

executeQuery("select b.login from Branch b where b.username = ?", username) 

我得到這個錯誤：

org.hibernate.QueryException: could not resolve property: bname of: Data.Entity.Branch 

但是當使用此代碼：

executeQuery("select b.login from Branch b where b.id = ?", username) 
it's return correct result 

我意味着這種類型的HQL的只是主鍵的工作？或我的地圖有問題？ 有什麼辦法可以使用其他字段（主鍵除外）形式可連接的表嗎？

Answer 1

Hibernate所期待您使用屬性名稱，而不是數據庫列名，即branchName insted的的bname和userName，而不是username。

所以，如果你改變你的查詢

executeQuery("select l from Login as l inner join l.branch as b " + 
    "where l.branch.branchName = ?", 
    username); 

和

executeQuery("select b.login from Branch b where b.userName = ?", username); 

，一切都應該正常工作。