Example: Grouping by common value


Input document:
<cities>
<city name="milan" country="italy" pop="5"/>
<city name="paris" country="france" pop="7"/>
<city name="munich" country="germany" pop="4"/>
<city name="lyon" country="france" pop="2"/>
<city name="venice" country="italy" pop="1"/>
</cities>
<table>
<tr>
<th>Country</th>
<th>City List</th>
<th>Population</th>
</tr>
<tr>
<td>italy</td>
<td>milan, venice</td>
<td>6</td>
</tr>
<tr>
<td>france</td>
<td>paris, lyon</td>
<td>9</td>
</tr>
<tr>
<td>germany</td>
<td>munich</td>
<td>4</td>
</tr>
</table>

Country City List Population
italy milan, venice 6
france paris, lyon 9
germany munich 4