休眠二级无方向映射

Question

I do not know if I explained myself in question, but basically I want to know if there is some functionality to map object that is not in direct relation with the target. For example:

|Table1   |   |Table2   |   |Table3   |
-----------   -----------   ----------
|id       |   |id       |   |id       |
|someValue|   |Table1_fk|   |Table2_fk|

and I could access Table2 object in class relation like this:

public class Table1 {
@Id
int id;
@Column
String someValue;
@OneToOne(mappedBy="Table2")
Table2 table2;
}

So my question is - can I map from Table1 to Table3?

Answer 1

Given your above code, it doesn't really sound like you need to "map", or even establish a relationship to, Table3.

Do you need properties from Table3 to just be available as part of Table1's API contract? If so, you can do something like:

public class Table1 {
    @Id
    int id;

    @Column
    String someValue;

    @OneToOne(mappedBy="Table2")
    Table2 table2;

    public Table3 getTable3() {
        return table2.getTable3();
    }
}

This assumes that the relationship is established in Table3, and 'mappedBy' in Table2, which is the sensible mapping given that Table3 actually contains the foreign key.