Hi all,
I would like to revive this old thread, which is representative of a few
other ones that can be found in the list with some effort. I understand
both the original proposal and the difficulty that Jeff pointed out.
But I think a very simple solution can be implemented if instead of
"parameterizing" the resultmap passing it a prefix at the point of use,
a facility is provided to duplicate a resultmap with a different
prefix using the original one as a template at the point of definition.
Maybe this can be regarded as a kind of extension to the resultmap:
<resultMap id="PrefixedResultMap" extends="SomeResultMap"
withPrefix="somePrefix_"/>
This is handy and I think that it brings no complex implementation
issues along.
I could work on a patch to support this feature, but I would like to hear
you opinion first.
Best regards
--
Carlos
> Jeff Butler
> Mon, 04 Dec 2006 09:44:51 -0800
>
> I understand the issue, and your proposed solution. I think the
> implementation could get complex - especially if the referenced result map
> referenced other result maps. Result processing is already pretty complex
> in iBATIS - this would add to that complexity.
>
> I'd like to hear from other users to see if this is a big need. My feeling
> is that this use case - where you populate different nested objects of the
> same type from a single query - is pretty rare.
>
> Jeff Butler
>
>
>
> On 12/4/06, Iwao AVE! <[EMAIL PROTECTED]> wrote:
>
> Hi all,
>
> It was a great news that [#IBATIS-225] had been implemented.
> I'm wondering if it can be improved a little bit more.
>
> --
> Assuming I have 2 simple java classes.
> Needless to say, there are corresponding tables in a database.
>
> public class Staff {
> Integer id;
> String name;
> // ... accessor methods
> }
>
> public class Section {
> Integer sectionId;
> Staff manager;
> Staff submanager;
> // ... accessor methods
> }
>
> To retrieve section with its manager and submanager, I will have a query
> like below.
>
> <select id="select" resultMap="sectionResult" resultClass="int">
> SELECT
> section.section_id,
> manager.staff_id AS manager_id,
> manager.staff_name AS manager_name,
> submanager.staff_id AS submanager_staff_id,
> submanager.staff_name AS submanager_staff_name
> FROM
> section,
> staff AS manager,
> staff AS submanager
> WHERE
> section.section_id = #value# AND
> section.manager_id = manager.staff_id AND
> section.submanager_id = submanager.staff_id
> </select>
>
> Then I will define the sectionResult resultMap.
> Currently, it may have to be like this, I suppose.
>
> <resultMap id="sectionResult" class="sectionClass">
> <result property="sectionId" column="section_id"/>
> <result property="manager.id" column="manager_staff_id"/>
> <result property="manager.name" column="manager_staff_name"/>
> <result property="submanager.id" column="submanager_staff_id"/>
> <result property="submanager.name" column="submanager_staff_name"/>
> </resultMap>
>
> Because both manager and submanager are instances of Staff, wouldn't it
> be nice to have a way to map these properties using externaly defined
> resultMap? (In my understanding, I can specify resultMap for one of
> manager or submanager, but not for both of them, right?)
>
> So, here's my proposal which introduces 'columnPrefix' attribute.
> On applying staffResult, iBATIS appends the prefix to the name of each
> column.
>
> <resultMap id="sectionResult" class="sectionClass">
> <result property="sectionId" column="section_id"/>
> <result property="manager" resultMap="staff"
> columnPrefix="manager_"/>
> <result property="submanager" resultMap="staff"
> columnPrefix="submanager_"/>
> </resultMap>
>
> <resultMap id="staffResult" class="staffClass">
> <result property="id" column="id"/>
> <result property="name" column="name"/>
> </resultMap>
>
> --
> If some of you like it, I will submit new improvement request to JIRA.
> Or, if iBATIS already has a way to achieve this, please show me how to
> do it.
>
> --
> Regards,
>
> Iwao
>
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