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Posted to ojb-user@db.apache.org by Marcus Breese <ma...@breese.com> on 2003/07/29 08:37:18 UTC
Query limiting by m:n relationship
I'm sorry for asking what may be a silly question, but is it possible
to query the database using a Criteria that includes a field that is in
a m:n relationship, but not intrinsically in the class.
For example:
class widget {
Integer id
String name
Collection allCategories() (ojb.collection to widget_category)
}
class category {
Integer id
String name
Integer parent_id
}
// indirection table/class
class widget_category {
Integer widgetId
Integer categoryId
}
With all of the associated tables and OJB mappings...
Is it possible to create a criteria that says "Give me all Widgets in
Category X"? Or is is possible to do a "query by example"?
-=-= -=-= -=-= -=-= -=-= -=-= -=-= -=-= -=-= -=-= -=-=-
Marcus Breese mbreese@iupui.edu
IU School of Medicine marcus@breese.com
Dept. of Biochemistry and Molecular Biology
Center for Medical Genomics / Grow Lab
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Re: Query limiting by m:n relationship
Posted by Marcus Breese <ma...@breese.com>.
As it turns out, this has been covered here before... so, just
disregard this redundant question.
Answer, in case anyone wants to know, is to use a Criteria where you
simply say:
Criteria c = new Criteria()
c.addEqualTo("allCategories.id","1");
(or something similar...)
Sorry for the duplicate... : )
On Tuesday, July 29, 2003, at 01:37 AM, Marcus Breese wrote:
> I'm sorry for asking what may be a silly question, but is it possible
> to query the database using a Criteria that includes a field that is
> in a m:n relationship, but not intrinsically in the class.
>
> For example:
>
> class widget {
> Integer id
> String name
>
> Collection allCategories() (ojb.collection to widget_category)
> }
>
> class category {
> Integer id
> String name
> Integer parent_id
> }
>
> // indirection table/class
> class widget_category {
> Integer widgetId
> Integer categoryId
> }
>
> With all of the associated tables and OJB mappings...
>
> Is it possible to create a criteria that says "Give me all Widgets in
> Category X"? Or is is possible to do a "query by example"?
>
> -=-= -=-= -=-= -=-= -=-= -=-= -=-= -=-= -=-= -=-= -=-=-
> Marcus Breese mbreese@iupui.edu
> IU School of Medicine marcus@breese.com
> Dept. of Biochemistry and Molecular Biology
> Center for Medical Genomics / Grow Lab
>
>
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: ojb-user-unsubscribe@db.apache.org
> For additional commands, e-mail: ojb-user-help@db.apache.org
>
>
>
-=-= -=-= -=-= -=-= -=-= -=-= -=-= -=-= -=-= -=-= -=-=-
Marcus Breese mbreese@iupui.edu
IU School of Medicine marcus@breese.com
Dept. of Biochemistry and Molecular Biology
Center for Medical Genomics / Grow Lab
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