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From "Clinton Begin" <clinton.be...@gmail.com>
Subject Re: Avoiding N+1 Selects
Date Tue, 20 Feb 2007 05:01:22 GMT
i.e. is it a join with a bridge table or not (1:M or M:N)?

Regardless, I wonder if a recursive result map would work....It might.

<resultMap id="Node" ... >
  <result name="children" ... resultMap="Node"/>
...

I don't see any reason why that would cause any problems...perhaps try it
and let us know.

Cheers,
Clinton

On 2/19/07, Clinton Begin <clinton.begin@gmail.com> wrote:
>
>
> Oh...is it a self join?
>
> Clinton
>
> On 2/19/07, Brad Handy <brad.handy@gmail.com> wrote:
> >
> > I guess I'll have to take a different approach.  The depth isn't set to
> > be a defined level; so if I go more than two levels below the grandparent,
> > it won't work.
> >
> > On 2/19/07, Clinton Begin <clinton.begin@gmail.com> wrote:
> > >
> > > You'll need one query with 3 result maps.  The result maps will be
> > > chained together with collection properties using the resultMap attribute.
> > >
> > >
> > > <resultMap id="Child">
> > >   ...
> > > <resultMap id="Parent">
> > >   <result ... resultMap="Child"/>
> > >   ...
> > > <resultMap id="GrandParent">
> > >   <result ... resultMap="Parent"/>
> > >   ...
> > > <select ... resultMap="GrandParent">
> > > ...
> > >
> > > The select statement should join the tables together and you may need
> > > to be very explicit with the column names.
> > >
> > > Clinton
> > >
> > > On 2/19/07, Brad Handy <brad.handy@gmail.com> wrote:
> > > >
> > > > I have a table which has all of the parent/child relationships in
> > > > the same table.  I would like to avoid the N+1 selects with this construct,
> > > > but it's unclear from the documentation if this can be done.
> > > >
> > > > Let's say I have the following relationships defined in the table:
> > > >
> > > > Grand Parent
> > > >    Parent 1
> > > >       Child 1
> > > >       Child 2
> > > >    Parent 2
> > > >    Parent 3
> > > >       Child 3
> > > >       Child 4
> > > >
> > > >
> > > > When creating the child objects for "Grand Parent", will the same
> > > > "Parent*" objects be used to add the children "Child*" objects to the
> > > > appropriate parents?
> > > >
> > > >
> > > >
> > > > Brad
> > > >
> > >
> > >
> >
>

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