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From "Clute, Andrew" <Andrew.Cl...@osn.state.oh.us>
Subject RE: Any plans for Reference filters?
Date Thu, 23 Sep 2004 19:05:15 GMT
Yeah, looking at the code that is used for the query customizer on
Collections, I would assume it would be real straight forward to add
that to references as well.

Now a quick question about how QC's work.

Assume my scenario of Person with addresses collection, and the need for
a 'filtered' Primary Address, property named 'primaryAddress'. If I did
something like this:

Sc.addEqualTo("person.primaryAddress.zipcode","90210");

Would it be smart enough to allow the customizer to add it's filtereing
on the JOIN query? Does it work that way for Collections right now?



-----Original Message-----
From: Jakob Braeuchi [mailto:jbraeuchi@gmx.ch] 
Sent: Thursday, September 23, 2004 2:59 PM
To: OJB Developers List
Subject: Re: Any plans for Reference filters?

hi andrew,

got me ! you're right query customizer only works for collections but
imo it should be possible for references as well. so we could have a
single concept for filtering.

jakob

Clute, Andrew schrieb:

> Can you put a query customizer on a reference descriptor? I thought 
> they were only for collections!
> 
> -Andrew
> 
>  
> 
> -----Original Message-----
> From: Jakob Braeuchi [mailto:jbraeuchi@gmx.ch]
> Sent: Thursday, September 23, 2004 12:59 PM
> To: OJB Developers List
> Subject: Re: Any plans for Reference filters?
> 
> hi andrew,
> 
> you could use a query customizer to manipulate reference queries. i 
> admit it's not as elegant as the filter but it's totally flexibel ;)
> 
> jakob
> 
> Clute, Andrew schrieb:
> 
>>I have run into a couple of scenarios where it would be extremely 
>>helpful to be able to add additional criteria to a reference
> 
> descriptor.
> 
>> 
>>For instance, you might have a Person object with a collection of 
>>Addresses on them. Address might have a property called "Primary". In 
>>your query, you might want to be able to qualify to use the primary 
>>address. The current way to do that is to keep a foreign key on your 
>>person table that links back to the primacy address object, and update
> 
> 
>>that when your primacy address changes. So, you have both a property 
>>on your object, and a db column.
>> 
>>It would be nice if you could still have that reference descriptor for
> 
> 
>>your person object for a Primary Address, but not maintain the foreign
> 
> 
>>key in the db, just had a certain criteria to the descriptor that 
>>filters it to the appropriate one.
>> 
>>For instance:
>> 
>><reference-descriptor
>>	name="primaryAddress"
>>	class-ref="pojo.Address"
>>	refresh="true"
>>	auto-retrieve="true"
>>	auto-update="false"
>>	auto-delete="false"
>>
>>	<foreignkey field-ref="personPK"/>
>>	<foreignkey-filter value="is_primary=1"/>
> 
> </reference-descriptor>
> 
>> 
>>Does that make sense? Just curious if this has ever been discussed.
>> 
>>Thanks!
>> 
>>-Andrew
>> 
>>
>>
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