Added: joinsetsCount to datasets that have joined datasets

sites/concepts/4_design.html

@@ -226,6 +226,7 @@ <h3>Placeholders for metadata</h3>
                 <tr><td>setNo</td><td>dataset</td><td>The running no of the dataset in the data recived.</td></tr>
                 <tr><td>setId</td><td>dataset</td><td>The id of the dataset in the datasouce. (must not be available, only if the datasource deliverd it's sets with id attribute)</td></tr>
                 <tr><td>setRef</td><td>dataset</td><td>The reference URI to the set in the datasource. (e.g. ref://navigation/get?id=1)</td></tr>
+                <tr><td>joinsetsCount</td><td>dataset</td><td>The number of datasets referenced to the set, if useing join attribute in WHERE.</td></tr>
                 <tr><td>attrName</td><td>attribute</td><td>The name of the attribute currently used.</td></tr>
                 <tr><td>attrId</td><td>attribute</td><td>The id of the attribute (thats a combination of attribute name and setid)</td></tr>
             </table>