ibatis-user-java mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Nathan Maves <Nathan.Ma...@Sun.COM>
Subject Re: N+1 with a twist?
Date Fri, 11 Feb 2005 20:54:41 GMT
This was all looking great but I hit a show stopper.

I have one parent table with 3 child tables.  The problem is that the 
child rows might or might not be there.  This means that I have to use 
an outer join to these tables.  Oracle only allows a table to have one 
outer join.  Suck!

Nathan

On Feb 11, 2005, at 1:37 PM, Clinton Begin wrote:

> Doesn't matter.  In series, or in parallel, any number of levels, any
> time any place.  It will work.
>
> Each resultMap="" mapping is treated separately.
>
> The coolest thing is that to do all of this it still only iterates
> over the result set a single time...  ;-)
>
> Cheers,
> Clinton
>
>
> On Fri, 11 Feb 2005 12:50:05 -0700, Nathan Maves 
> <Nathan.Maves@sun.com> wrote:
>> How about 3 levels deep?
>>
>> A from request
>>         List of B from products
>>         List of C from approvals
>>                 User object from users (where user's id maps to a 
>> column in the
>> approvals table)
>>
>>
>> Nathan
>>
>> On Feb 9, 2005, at 10:30 AM, Clinton Begin wrote:
>>
>>> If you can join the data into a single resultset with repeating
>>> groups, the N+1 solution will work, no matter how the collections are
>>> arranged.
>>>
>>> As long as you group by some column in table_a, you can separately 
>>> map
>>> 2 collections on the same class.
>>>
>>> This will work.
>>>
>>> Try it out!
>>>
>>> Clinton
>>>
>>> On Wed, 09 Feb 2005 10:21:54 -0700, Nathan Maves
>>> <Nathan.Maves@sun.com> wrote:
>>>> I dont think that the current implementation will work for this but 
>>>> I
>>>> was looking for some best practices on how to do it.
>>>>
>>>> Parent Class A has n number of List properties that all come for 
>>>> their
>>>> own tables.
>>>>
>>>> A from table_a
>>>>         List of B from table_b
>>>>         List of C from table_c
>>>>         .
>>>>         .
>>>>         .
>>>>
>>>>
>>>> Nathan
>>>>
>>>>
>>
>>


Mime
View raw message