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From "Niels Beekman" <ni...@wis.nl>
Subject RE: TypeHandlerCallback and lazy loading
Date Tue, 31 May 2005 16:35:00 GMT
I use the typehandlers to retrieve other classes that are not managed by iBATIS, but to pass
columnvalues transparently, so I do not have to store all kinds of int's in my classes but
declare the properties directly of the appriopriate type.

I don't know which data has to be retrieved at forehand, so it is rather pointless to fetch
my whole DB, just in case someone requests that data :)

Niels
________________________________________
From: Clinton Begin [mailto:clinton.begin@gmail.com] 
Sent: dinsdag 31 mei 2005 17:48
To: ibatis-user-java@incubator.apache.org
Subject: Re: TypeHandlerCallback and lazy loading

Lazy loading won't reduce the number of queries, unless you're never accessing the data you're
retrieving, in which case I'd ask why you're loading it at all.

Consider joining the data and mapping it with groupBy="" and a nested resultMap.  This faq
might help

http://opensource.atlassian.com/confluence/oss/display/IBATIS/How+do+I+get+around+the+N+Plus+1+selects+problem%3F


Cheers,
Clinton
On 5/31/05, Niels Beekman <niels@wis.nl> wrote:
Hi,

I've successfully used TypeHandlerCallback to load some complex
datatypes. Now I'm facing the following problem: I have a resultmap
which has 5 typehandler-definitions, when I load an object using this
resultmap, the typehandlers are called instantly, which cause lots of
DB-queries to be executed.

Is there a way to enable lazy loading for typehandlers? Maybe to keep
the ResultGetter in cache and only execute a special construction-method 
when the property is requested?

Thanks for your thoughts,

Niels


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