4.5.8.4. <sortBy> sorting clause

The <sortBy> parameter is used to specify a list of property names whose values should be used to order the set of city objects that satisfy the query. If no sorting clause is provided, the city objects are exported in an arbitrary order.

The value of the <sortBy> parameter is a list of one or more <sortProperty> elements, each of which must define a <valueReference> pointing to the property that shall be used for sorting. Only simple thematic attributes of the requested top-level feature type or one of its nested feature types are supported. If you specify multiple <sortProperty> elements, the result set is sorted by the first property in the list and that sorted result is sorted by the second property, and so on.

For each <sortProperty>, the sort order can be defined using the <sortOrder> parameter. The value asc indicates an ascending sort (default) and desc indicates a descending sort.

The following example illustrates how to sort all buildings according to their measured height in descending order.

<query>
  <typeNames>
    <typeName>bldg:Building</typeName>
  </typeNames>
  <sortBy>
    <sortProperty>
      <valueReference>bldg:measuredHeight</valueReference>
      <sortOrder>desc</sortOrder>
    </sortProperty>
  </sortBy>
</query>