First, a simplified version of the database:

Table A: (type = 1)
-id

Table B: (type = 2)
-id

Table C: (type = 3)
-id

Table Z:
-id
-type_id
-fk_id

I have multiple tables that need to access one table based on their type (an Integer value). Table A, B, and C, will always have one and only one table Z association and that association is defined by matching the id of table A, B, or C to the fk_id and matching type_id in table Z. Ideally, I would prefer to not include the Table Z id in A, B, or C, and I would also not like individual columns for type_ids in A, B, and C.

Sample Data:

Table A: (Type = 1)
id
1
2

Table B: (Type = 2)
id
1

Table C: (type = 3)
id
1
2

Table C:
id type_id fk_id
1 1 1
2 1 2
3 2 1
4 3 1
5 3 2

I've tried adding @Where, @Filter, @Formula, etc onto the @OneToOne relationship with no avail. Is this type of association even possible in annotations, or will I need to use HQL?

Example of what would be ideal (if the where annotation actually worked in one to one relationships) :

Table Z
@OneToOne(targetEntity=A.class)
@JoinColumn(name="fk_id", referencedColumnName="id")
@Where(clause="type_id=3")
private A a;

Table A
@OneToOne(mappedBy="a", targetEntity=Z.class)
private Z z;

Any advice would be greatly appreciated, thanks.

EDIT: I apologize that my formatting did not work very well for the example data.