HOW to put restrictions on map keys

adeon · **Joined:** Wed Jan 09, 2008 8:33 am **Posts:** 4

I have a ternary association, which is represented by the following map:

Code:

<class name="Actor" table="Actor">
    ...
    <map name="fieldValues" table="ActorFieldValues">
      <key column="ownerID" />
      <map-key-many-to-many column="fieldID" class="Field" />
      <many-to-many column="valueID" class="FieldValue" />
    </map>
</class>

I want to find all objects (actors) whose fieldValues keys match some restrictions.
Is it possible to do using a HQL query (especially using Criteria)?

AD

farzad · **Posted:** Wed Jan 09, 2008 11:14 am

adeon wrote:

I have a ternary association, which is represented by the following map:

Code:

<class name="Actor" table="Actor">
    ...
    <map name="fieldValues" table="ActorFieldValues">
      <key column="ownerID" />
      <map-key-many-to-many column="fieldID" class="Field" />
      <many-to-many column="valueID" class="FieldValue" />
    </map>
</class>

I want to find all objects (actors) whose fieldValues keys match some restrictions.
Is it possible to do using a HQL query (especially using Criteria)?

AD

I do believe in HQL you can use a join and specify an extra filter for the join by using WITH keyword. This is an example from hibernate document:

Code:

from Cat as cat 
    left join cat.kittens as kitten 
        with kitten.bodyWeight > 10.0

Is this what you are looking for?

Farzad-

adeon · **Joined:** Wed Jan 09, 2008 8:33 am **Posts:** 4

farzad wrote:

Code:

from Cat as cat 
    left join cat.kittens as kitten 
        with kitten.bodyWeight > 10.0

Is 'kittens' a map in this example? I suppose not. When you are referring to kitten.bodyWeight how do you know that you are referring to an attribute of the map key entity, NOT the value?

AD

adeon · **Joined:** Wed Jan 09, 2008 8:33 am **Posts:** 4

In other words, I want to set restrictions on map keys using Criteria API.

farzad · **Posted:** Wed Jan 09, 2008 12:17 pm

adeon wrote:

In other words, I want to set restrictions on map keys using Criteria API.

I see your point. I am working on an example to see how this works. I will get back to you if I find something useful.

Farzad-

farzad · **Posted:** Wed Jan 09, 2008 1:11 pm

farzad wrote:

adeon wrote:

In other words, I want to set restrictions on map keys using Criteria API.

I see your point. I am working on an example to see how this works. I will get back to you if I find something useful.

Farzad-

I didn't come up with anything useful here but one thing I recommend you look into is to model the relation as a separate class instead of using the map thing and you will have a lot more control on queries.

Farzad-

afable · **Joined:** Wed Jun 06, 2007 10:17 pm **Posts:** 1

With HQL, you can:
supposing a class Actor, actions is a Map property, "suspend" is Map's key,
createQuery("select a from Actor a where a.actions['suspend'] = ?"). ...

but Criteria don't support the criterion based map