Is there a way of reusing the same resultMap multiple times in a single query.
For example, suppose I have a "foo" resultMap:
<resultMap id="foo" class="Foo">
<result property="Bar" column="bar" />
</resultMap>
Is there a way to define another resultMap that reuses the above for different columns? Something like...
<resultMap id="fizz"class="Fizz">
<result property="Foo1" column="bar=bar1" resultMapping="foo" />
<result property="Foo2" column="bar=bar2" resultMapping="foo" />
<result property="Foo3" column="bar=bar3" resultMapping="foo" />
</resultMap>
Almost. If you select the ID of the Foo in your query, you can have the Fizz result map execute a SELECT for that ID, which will use the Foo result map.
<result property="Foo1" column="bar1Id" select="selectFoo"/>
(Assuming you have a selectFoo query defined.) But that's extremely slow with large result sets, since it does an additional SELECT for every row.
iBATIS has a solution to this problem for the typical case, where you have a composite object that contains various other objects. First, you define a query that joins your tables, then you can use fooMap to populate a Foo:
<result property="Foo1" resultMap="fooMap"/>
But you can't use that result map twice for two different Foos because the result map specifies certain column names. You can use another technique, though:
<result property="foo1.bar" column="foo1bar"/>
<result property="foo2.bar" column="foo2bar"/>
More detail in page 35 of the iBatis Datamapper manual.