Thanks very much for your help, Ole. This solved my problems, though I would
like to add a few of my own observations:
(1) Is it necessary to create the composite result map
(id="CompositeTopResult")? I added the lines below:
<result property="subClassProperty1" resultMap="SubResult1"/>
<result property="subClassProperty2" resultMap="SubResult2"/>
Directly into the "TopResult" resultMap and had no problems.
(2) The resultMap/result syntax diagram on page 31 of the manual seems to
suggest that column is a mandatory attribute of result when in fact it is
not. This contributed to my initial confusion.
(3) One oddity I encountered was that the resultMap reference needs to be
fully qualified with the name-space in front. I don't know if this is a bug
of feature, but simply using resultMap="Subresult1" resulted in an error
saying the resultMap is not defined. When I qualified it with the namespace,
everything worked, even though both result maps (TopResult and SubResult1)
are defined in the same namespace.
Thanks again for you help.
amin
On 8/9/07, Ole Trenner <[EMAIL PROTECTED]> wrote:
>
> If I get you right you could use a resultMap that itself uses other
> resultMap instances to populate its subclass attributes.
>
> Lets say, you have got a select like "SELECT * FROM mytable" that
> returns a resultSet of 103 columns, several of which get mapped to the
> top-level class with a resultMap like so:
>
> <resultMap class="package.TopClass" id="TopResult">
> <result column="id" property="id"/>
> <result column="property1" property="property1"/>
> <result column="property2" property="property2"/>
> ...
> <result column="propertyN" property="propertyN"/>
> </resultMap>
>
> Now you create a resultMap for every subset class like so:
>
> <resultMap class="package.SubClass1" id="SubResult1">
> <result column="subProperty1" property="subProperty1"/>
> <result column="subProperty2" property="subProperty2"/>
> ...
> </resultMap>
>
> <resultMap class="package.SubClass2" id="SubResult2">
> <result column="subProperty3" property="subProperty3"/>
> <result column="subProperty4" property="subProperty4"/>
> ...
> </resultMap>
>
> Now you can create a "composite" resultMap that uses all those
> resultMaps to create a TopClass instance filled with each of its
> properties and its SubClass properties:
>
> <resultMap class="package.TopClass" extends="TopResult"
> id="CompositeTopResult">
> <result property="subClassProperty1" resultMap="SubResult1"/>
> <result property="subClassProperty2" resultMap="SubResult2"/>
> </resultMap>
>
> Your select now can use this resultMap to populate a complete TopClass
> instance with both its flat fields and its subclass instances.
>
> Hope that helps :)
> Best regards -
> Ole.
>
>
> Amin Ahmad wrote:
> > Hello,
> >
> > I am working with a 103-column table that tracks a variety of
> > information for a provider. Rather than modeling this as a single class
> > with 103 attributes, I have defined a top-level class that contains a
> > few core provider attributes, and "subject-area" classes that group
> > disjoint subsets of attributes by domain ( e.g. Financial, Metrics,
> > Demographics). The top level bean contains an attribute for each of
> > these "subject-area" classes.
> >
> > My problem lies in effectively using iBatis to populate this structure
> > from a table row. My current approach is to use a custom type handler to
> > populate the subject area bean. The example below shows how I am
> > populating the "metrics" attribute in the resultMap of the top-level
> > provider class.
> >
> > <result property="metrics"
> > column="QT_ETHR_AVLB_RSTR"
> >
> > typeHandler="com.cgi.wasacwis.typehandlers.ProviderMetricsTypeHandler"/>
> >
> > The metrics attribute is actually a "subject-area" class that holds ~20
> > attributes from the row. The custom type handler,
> > ProviderMetricsTypeHandler , contains code for creating and populating
> > the fields. To illustrate, I have included the method "getResult" below:
> >
> > private ProviderMetrics getResult(ResultSet r) throws SQLException {
> > ProviderMetrics result =
> > WasacwisFactory.eINSTANCE.createProviderMetrics();
> >
> > result.setEitherAvailableRestricted
> > (r.getLong("QT_ETHR_AVLB_RSTR"));
> > result.setEitherProviderRestricted
> > (r.getLong("QT_ETHR_PRVD_RSTR"));
> > result.setFemaleAvailableRestricted
> > (r.getLong("QT_FEML_AVLB_RSTR"));
> > result.setFemaleProviderRestricted
> > (r.getLong("QT_FEML_PRVD_RSTR"));
> > result.setMaleAvailableRestricted
> > (r.getLong("QT_MALE_AVLB_RSTR"));
> > result.setMaleProviderRestricted
> > (r.getLong("QT_MALE_PRVD_RSTR"));
> > result.setProviderParticipantsUnder18
> > (r.getLong("QT_PRVD_PART_UND18"));
> > result.setProviderParticipantsUnder2
> > (r.getLong("QT_PRVD_PART_UNDR2"));
> > result.setTotalAvailableBedCapacity
> > (r.getLong("QT_TOT_AVLB_BEDCAP"));
> > result.setTotalAvailableRestricted
> > (r.getLong("QT_TOT_AVLB_RSTR"));
> > result.setTotalAvailableUnder18
> > (r.getLong("QT_TOT_AVLB_UNDR18"));
> > result.setTotalAvailableUnder2
> > (r.getLong("QT_TOT_AVLB_UNDR2"));
> > result.setTotalEitherPlaced
> > (r.getLong("QT_TOT_ETHR_PLCD"));
> > result.setTotalEitherReserved
> > (r.getLong("QT_TOT_ETHR_RSVD"));
> > result.setTotalFemalePlaced
> > (r.getLong("QT_TOT_FEML_PLCD"));
> > result.setTotalFemaleReserved
> > (r.getLong("QT_TOT_FEML_RSVD"));
> > result.setTotalMalePlaced
> > (r.getLong("QT_TOT_MALE_PLCD"));
> > result.setTotalMaleReserved
> > (r.getLong("QT_TOT_MALE_RSVD"));
> > result.setTotalPlaced
> > (r.getLong("QT_TOT_PLCD"));
> > result.setTotalPlacedUnder18
> > (r.getLong("QT_TOT_PLCD_UNDR18"));
> > result.setTotalPlacedUnder2
> > (r.getLong("QT_TOT_PLCD_UNDR2"));
> > result.setTotalProviderBedCapacity
> > (r.getLong("QT_TOT_PRVD_BEDCAP"));
> > result.setTotalProviderRestricted
> > (r.getLong("QT_TOT_PRVD_RSTR"));
> > result.setTotalReserved
> > (r.getLong("QT_TOT_RSVD"));
> > result.setTotalReservedUnder18
> > (r.getLong("QT_TOT_RSVD_UNDR18"));
> > result.setTotalReservedUnder2
> > (r.getLong("QT_TOT_RSVD_UNDR2"));
> >
> > return result;
> > }
> >
> > Needless to say, I am writing the entire mapping for the provider
> > metrics class in Java, and this isn't making good use of iBatis. Can
> > anyone suggest a better strategy?
> >
> > thank you,
> > Amin
>
>
