queryForMap returning zero results

["Firas A." <of...@idigna.com>]

Hello everybody!

I'm getting zero results when using queryForMap. Whith queryForList I get
the correct results.

----- SQLMap -----
<resultMap id="listOfCategories"
class="com.mycompany.ecommerce.ProductCategory">
        <result column="product_category_id" property="productCategoryId"
jdbcType="VARCHAR" />
        <result column="parent_category_id" property="parentCategoryId"
jdbcType="VARCHAR" />
        <result column="category_name" property="categoryName"
jdbcType="VARCHAR" />
</resultMap>

<select id="listAvailableCategories" resultMap="listOfCategories">
        SELECT
              product_category_id,
              parent_category_id,
              category_name
        FROM  product_category
</select>

----- Java -----
public Map listAvailableCategories() throws SQLException {
        Map prodCatRel = sqlMapClient.queryForMap("listAvailableCategories",
null, "productCategoryId");
        return prodCatRel;
}

In the logging output I can clearly see that there are several rows in the
resultset, but prodCatRel.size()==0. 
 
Anybody have an idea? 
 
Thanks for your time! 
 
</Firas>