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iBATIS sqlmap with groupby how to prevent null record on child

Need help with sqlmap group by. Im getting an empty child object when there is no child relationship 

<resultMap id="GrpMap" class="Grp" groupBy="GroupId">
   <result column="grp_id" property="GroupId" jdbcType="UUID"/>
   <result column="nm" property="name" jdbcType="VARCHAR"/> 
   <result property="children" resultMap="Groups.childMap"/>
</resultMap>


<resultMap id="childMap" class="child">        
    <result column="child_ky" property="childKey" jdbcType="UUID"/>
    <result column="name" property="name" jdbcType="VARCHAR"/>
</resultMap>

is there a way of specifying that if there is no children then not to populate the relationship? my sql query is a left outer join so will return null records for the child.

I want to do something like isnotNull column="child_ky" so the child does not get populated

<resultMap id="GrpMap" class="Grp" groupBy="GroupId">
   <result column="grp_id" property="GroupId" jdbcType="UUID"/>
   <result column="nm" property="name" jdbcType="VARCHAR"/> 
   <isnotnull child_ky>
   <result property="children" resultMap="Groups.childMap"/>
   </inotnull>
</resultMap>
Solution

  • iBatis offers the notNullColumn parameter for the result tag:

    <resultMap id="GrpMap" class="Grp" groupBy="GroupId">
  [...]
  <result property="children" resultMap="Groups.childMap" notNullColumn="child_ky"/>
</resultMap>