Examples of queries

You can run a query on any feature property other than centerline. Criteria can be numeric or non-numeric. You can also run a zone query. All zones in the query should be of the same type. For example, do not mix local default zones with crossing zones in a single zone query.

Example 1: Run a feature query

Create a simple collection of all rivers that are less than 20 meters wide, change the crossing type to three cells of a particular type of culvert, and change the color to a different shade of blue to highlight the new requirements.

  1. On the General tab, click Query.

  2. Leave the Object field as Feature.

  3. Under Property, select Nature.

  4. Leave the Operator as =.

  5. From the Value list, select River.

  6. Click New set.

    All of the rivers within the study area are selected. The next step is to select those rivers that are less than 20 meters wide.

  7. Open the Query dialog again. (See Step 1.)

  8. Leave the Object field as Feature.

  9. Under Property, select Width.

  10. From the Operator list, select <.

  11. From the Value list, select 20.00.

  12. Click Select from set.

    The software creates a subset of the original set. The subset meets an additional criterion. You can keep repeating the process to create a final collection that satisfies three or four criteria.

    Quantm Desktop software discards all rivers that are more than 20 meters in width.

  13. Use the Feature Properties window to make the required changes to the objects still selected from the query:
    1. Change the Crossing type to Culvert.
    2. Set Culvert type to 1500mm box.
    3. Set the number of cells to 3.
    4. Change the Color setting to the new color.

Example 2: Run a feature query

Create a more complex collection that includes all roads wider than 20 meters and all rivers wider than 30 meters.

  1. Create a new layer called Temp.
  2. Create a collection of all roads wider than 20 meters. Follow the method described above in Example 1, but set the Operator field to >.

  3. Add the road collection into the new Temp layer.

  4. Create a collection of all rivers wider than 30 meters. Move these to the layer called Temp.

    Note: When you click Add to set, the software adds objects that meet the new criterion to the original set.

  5. Select all features in the Temp layer. To do this, run a query to select all features in the Temp layer. Or, open the Temp layer in the Layer pane and then directly select all objects in the layer.