I am trying to define a subclass matching a discriminator-value that can be either of 2 possible values, ie. is in ["a", "b"]. Is this possible?

E.g. in the example below, a "sportsfan" can be a "soccerFan", a "tennisFan" or BOTH. I do NOT want to create a separate object "soccerTennisFan" for the latter.


<class name="sportsFan" table="sportsfan">
..
<discriminator column="fanType" type="integer" />

..
<subclass name="soccerFan" discriminator-value="1">
<subclass name="tennisFan" discriminator-value="2">



(The corresponding descriminator value for a fan that belongs to BOTH would be 3.)


I already looked at using a formula in the discriminator, sth. like

<discriminator "case when FAN_TYPE in ("1","3") then "soccerfan" else when FAN_TYPE in ("2","3") then "tennisFan" else "otherFan" />


However, in this case if FAN_TYPE is 3 (ie. soccer AND tennis fan), he would always come out as a soccer fan only.


Another option I see would be using multiple discriminators (e.g. first = "isSoccerFan", second = "isTennisFan"), but I don't think Hibernate supports such.



Any help/ideas appreciated.

Do you want to ceate 2 objects of sportsFan namely tennisfan , soccerfan if the value is 3.??

The DB has only 1 table, ie. SPORTSFAN. SoccerFan and TennisFan both extend the SportsFan object.

A sportsfan who is both, a soccerFan and a tennisFan, is stored only once in the DB SPORTSFAN table with TYPE set to 3.

So, if value/type is 3, I want to access this dataset as a soccerFan object as well as as a tennisFan object.

Example: SPORTSFAN DB Table

ID Name Type
---------------------------------
1 John 1
2 James 2
3 Frank 3

If I query the DB/Hibernate with SELECT all SOCCERFAN, I want to get John and Frank. (Here, Frank will be treated as a soccerFan object.)

If I query the DB/Hibernate with SELECT all TENNISFAN, I want to get James and Frank. (Here, Frank will be treated as a tennisFan object.)

use entity-name

max,

Thanks for the suggestion. But I don't see how this solves my problem. Any further lead?


Another option that I can think of would be to use a regular expression in the discriminator-value. Anybody any idea whether such is supported? (and if so, how?)

Cheers

have 2 mappings for the same class, but different entity-name.

Max, Thanks again.

If I understand you correctly, this would imply that I have to create a third type of Java object "soccerTennisFan" which I don't want to do.

Reason: There are many possible types of "fans", ie. many different combinations. Creating a separate object for each would blow up the object model.

From a screen perspective, I will always access the type=3 fan either as a "soccerFan" or as a "tennisFan" but never as a "soccerTennisFan" object. That is why I was looking for a flexible descriminator-value like descriminator-value in [1, 3].

As it seems that such is not possible with Hibernate, I probably have to use "JOINED-SUBCLASS" and create 2 additional index tables in the DB, 1 storing the soccerFan IDs, 1 storing the tennisFan IDs.

Any comment / further idea?

NO - you don't need a third type. You just need to use a different entity-name. entity-name != class name.

/max

Many thanks Max.

M