Attribute Query

The Attribute Query interface is used to define a query expression based on attributes and to show all objects obtained when the query is applied. A query expression is defined by a restriction clause (WHERE clause) over a pre-visualized Layer. It is advised to show the attributtes table too.

It is accessible through:

Layer Explorer > Right Click over an layer name > Attribute Query...
or
Layer > Attribute Query...

This interface consists of the following steps:
  1. Restriction - Defines the restriction clause.
    • Attribute name               Operator            Attribute value
    • q1
  2. SQL Result - It shows the text corresponding to the SQL acquired above (it is not editable).
  3. Layer Selection options:
    • Add: it adds the query result to the ones already selected.
    • New: it removes the previously selected items and shows only the new ones selected by this query.
    • None: it clear previously selected items from the Map Display and  prepares for a new query.
  4. Apply: Apply the query restriction with one of the options (add, New, None) and check the result.
    • Note: The color used to highlight the selected objects can be changed through the Selection Style (default is green) associated to the layer (close this interface to be able to change it).
  5. Query Layer: (saving your query)
    • Name: it shows the layer name.
    • Create Layer: press here to create a Query Layer (a special kind of layer will appear into the Layer Explorer with the same name). 
    • Close this interface and go to the Layer Explorer to visualize the Query Layer created.qlayer

Alternatively to item 5, it is possible to create a new real Layer with the selected objects (instead of a Query Layer). Follow the steps below:
  1. Close - keep the selected objects on the Map Display and press close.
  2. Go to the Layer Explorer -> Right Click over the layer name
  3. Choose: Save Selected Objects...
  4. Choose a new name to the Layer.
  5. The new layer will have only the selected objects.