Is there a way to include the table name in the column resultmap
definitions generated by ibator?
This would be very useful when having joins with column name collisions:
An example:
- TABLE "PRODUCT" having ID and NAME columns
- TABLE "CATEGORY" having ID and NAME columns
Ibator generated resultmaps currently look like:
<resultMap class="test.Product" id="productResult">
<result column="ID" jdbcType="INTEGER" property="id" />
<result column="NAME" jdbcType="VARCHAR" property="name" />
</resultMap>
<resultMap class="test.Category" id="categoryResult">
<result column="ID" jdbcType="INTEGER" property="id" />
<result column="NAME" jdbcType="VARCHAR" property="name" />
</resultMap>
Now I want to extend the generated sqlmap to add the category to every
product as follows:
<resultMap class="test.Product" extends="productResult"
id="productWithCategoryResult">
<result property="category" resultMap="CATEGORY.categoryResult " />
</resultMap>
The select would look like:
<select id="selectProductsWithCategory"
resultMap="productWithCategoryResult">
select PRODUCT.*, CATEGORY.*
where CATEGORY.ID = PRODUCT.CATEGORY_ID
</select>
Without having the tablenames in the resultmap, ibatis does not know
which ID or NAME column to map to which object. So I end up having the
value of PRODUCT.ID and PRODUCT.NAME in my created Category instance.
Serveral posts suggest to not use wildcards in the select statement and
to define column aliases to avoid column name collisions. But this is
very tedious and you have to write your own join resultMaps to match
with the column defined aliases aswell.
A working solution is to change the ibator generated resultmaps to
include the table name in the column attribute:
<resultMap class="test.Product" id="productResult">
<result column="PRODUCT.ID" jdbcType="INTEGER" property="id" />
<result column="PRODUCT.NAME" jdbcType="VARCHAR" property="name"
/>
</resultMap>
<resultMap class="test.Category" id="categoryResult">
<result column="CATEGORY.ID" jdbcType="INTEGER" property="id" />
<result column="CATEGORY.NAME" jdbcType="VARCHAR"
property="name" />
</resultMap>
Works like a charm, but every time I re-generate the sqlmaps my changes
are thrown away and I have to make them again by hand. I searched the
mailing list and found out that you can define an "alias" for each
table, but this isn't helping in my case either.
If it can't already be done somehow, my suggestion would be to include
an "includeTablenameInColumns" switch in ibator.
Thanks for your help,
B. Behler
