<dataConfig>
    <dataSource type="JdbcDataSource" name="ds-wordpress" driver="com.mysql.jdbc.Driver" url="jdbc:mysql://localhost:3306/wordpressdb" user="<username>" password="<password>" />
    <dataSource name="ds-sql" driver="com.microsoft.sqlserver.jdbc.SQLServerDriver" url="jdbc:sqlserver://localhost:1433;databaseName=sqldb" user="<username>" password="<password>" />

    <document name="articles">

        <entity dataSource="ds-sql" pk="ID" name="stats" query="SELECT * FROM stats WHERE objecttype=110">
            <field name="id" column="ID" />
            <field name="objectid" column="ID" />
            <field name="objecttype" column="ID" />
        </entity>

        <entity dataSource="ds-wordpress" pk="ID" name="article" query="SELECT p.*, ( SELECT guid FROM wp_posts WHERE id = m.meta_value ) AS imgurl
FROM wp_posts p
LEFT JOIN  wp_postmeta m ON(p.id = m.post_id AND m.meta_key =  '_thumbnail_id' )
WHERE p.post_type =  'post'
AND p.post_status =  'publish';">
            <field name="id" column="ID" />
            <field name="post_title" column="post_title" />
            <field name="imgurl" column="imgurl" />

            <field name="viewcounter" column="viewcounter" />
        </entity>
    </document>
</dataConfig>