SOLR: dataImportHandler and Oracle

We are going to test the latest version of SOLR (3.3) and we need to populate it with data that is as close as the what we have on production. However, the script that populates the production index will not work with the new version because there are fields that were taken out due to localSOLR not being used with 3.3. Thus, a data-config.xml was created to be used by the data import handler.

Reviewing the schema.xml, I was caught by surprise with this definition:

  <field name="AD_ID" type="text" indexed="true" stored="true" required="true"/>
  <dynamicField name="PHOTO_*"  type="string"  indexed="true"  stored="true"/>

And the output is similar to this:

<str name="AD_ID">1</str>

<str name="PHOTO_1">image_1.jpg,</str>

<str name="PHOTO_2">image_2.jpg,</str>

<str name="PHOTO_3">image_3.jpg,</str>

<str name="PHOTO_4">image_4.jpg,</str>

<str name="PHOTO_5">image_5.jpg,</str>

How  can we achieve this? We can create a user-defined transformer using JAVA script. Here's what my data-config.xml would look like:

<dataConfig>
<dataSource driver="oracle.jdbc.driver.OracleDriver"
            url="jdbc:oracle:thin:@//hostname.com:port/SID"
            user="username" password="password" />
<script>
  <![CDATA[
    function photoFunction(row) {
      var seqNum = row.get("SEQ_NUM");
      var imageName = row.get("IMAGE_NAME");
      var fieldName = "PHOTO_" + segNum;
      row.put(fieldName, imageName);
      return row;
    }
  ]]>
</script>
<document name="Doc">
  <entity name="Ad" pk="AD_ID"
          query="select a.ad_id, a.other_columns
                   from table_name a
                   where conditions">
    <entity name="Photo"
            query="select p.seq_num, p.image_name
                     from photo_table p
                     where p.ad_id = '${Ad.AD_ID}'
                     order by p.display_order"
            transformer="script:photoFunction" />
  </entity>
</document>
</dataConfig>

A MySQL database can also be used by changing the dataSource part.