如何从HQL表单中的两个连接表查询中选择*？

Question

I had two hibernate entity here with annotation:

@Entity
@Table(name = "CLIENT")
public class Client {

    private Long pkClient;
    private String name;

    @Id
    @GeneratedValue(strategy=GenerationType.AUTO)
    @Column(name="PK_CLIENT")
    public Long getPkClient() {
        return pkClient;
    }
    public void setPkClient(Long pkClient) {
        this.pkClient = pkClient;
    }

    @Column(name="NAME")
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }

    ...
}

@Entity
@Table(name="ACCOUNT")
public class Account {

    private Long pkClientAccount;
    private Long fkClient;
    private String accountNo;

    @Id
    @Column(name="PK_CLIENT_ACCOUNT")
    @GeneratedValue(strategy=GenerationType.AUTO)
    public Long getPkClientAccount() {
        return pkClientAccount;
    }
    public void setPkClientAccount(Long pkClientAccount) {
        this.pkClientAccount = pkClientAccount;
    }

    @Column(name="FK_CLIENT")
    public Long getFkClient() {
        return fkClient;
    }
    public void setFkClient(Long fkClient) {
        this.fkClient = fkClient;
    }

    @Column(name="ACCOUNT_NO")
    public String getAccountNo() {
        return accountNo;
    }
    public void setAccountNo(String accountNo) {
        this.accountNo = accountNo;
    }

    ...
}

The relationship is one-to-many which a Client has many Account. Table ACCOUNT has foreign key (FK_CLIENT) to table CLIENT's primary key (PK_CLIENT).

I want to perform this query in HQL form:

select * from ACCOUNT a inner join CLIENT b on a.FK_CLIENT = b.PK_CLIENT

This mean, all properties from Account and Client entity will be selected.

Anyone know how to make that query in HQL form?

AFAIK, in HQL we can only select one entity.

Note:
I cannot use @ManyToOne mapping in Account entity because there is already fkClient property and I can't change this because the get/setFkClient has already been used in other places.

The code above has been simplified by removing unrelated parts to make easier to read. If you find a typo, please let me know in the comment section since I typed the code manually.

Answer 1

Yes, you can select several entities with HQL. Hibernate will return an array of type Object[].

select 
    account, 
    client 
from Account account, Client client 
where account.fkClient = client.pkClient

Answer 2

With Hibernate 5.1 , it's now possible to join entities even if the mapping doesn't mirror the database table relationship.

So, this HQL query is valid from Hibernate 5.1:

select 
    account, 
    client 
from Account account 
join Client client on account.fkClient = client.pkClient

Answer 3

Try following HQL

select account from Account account, Client client where account.fkClient = client.pkClient

For more details please refer Hibernate reference documentation http://docs.jboss.org/hibernate/orm/3.6/reference/en-US/html/queryhql.html#queryhql-where

Answer 4

You can use:

select * from  TB_1 as a 
left join  TB_2 as b 
on a.ID_TB_1 = b.ID_TB_2 and b.ID_TB_2 is null