Hibernate HQL Statement Considerations

There are now entity classes Student and user.

public class student{

Private String ID;

Private Sting classroom;

private user user;

@Id
@GeneratedValue (generator = "Paymentablegenerator")
@GenericGenerator (name = "Paymentablegenerator", strategy = "uuid")
@Column (name = "ID", nullable=false,length=36)
Public String getId () {
   return this.id;
}

@ManyToOne (fetch = Fetchtype.eager)
@JoinColumn (name = "USER")
@ForeignKey (name= "null")
Public USER GetUser () {
   return user;
}
public void SetUser (user user) {
   This.user = user;
}
......

}

public class user{

Private String ID;

private String name;

private String password;

......

}

If you don't use Select Direct "from Student" to find

HQL statement: "From Student where user= ' 123456 '"

Then the where is directly appended with "where user= ' 123456 '" (123456 is the ID of the user table record).

If you want to use select "Select Classroom ..." to find

HQL statement: "Select" Select Classroom,user.name as User from Student where uder.id= ' 123456 ' "

Then the where statement already has the user in select already an object to add. (123456 is the ID of the user table record).

You use a SELECT, then you do not persist with hibernate hql, because you get the result is no longer entity class, get results also can not use list<studet>, became list<object[]> ...

It's hard--it's better to just use SQL to get the results list<object[]>

Hibernate HQL Statement Considerations