III. d. ii. Make Selections based on queries
             Estimated time:
             5 minutes
Here you will be able to reduce the selection of the graphical elements using a number of boolean operators. Such as, get me all those that are greater than 50... then only those are selected.
In this exercise, you will:
  • Query the GIS borrow site attributes with the "Select by Attribute" feature.
  • Locate the sites with the general soil type(s) that could be used for your project.
  • Use the logic key button to select more than one type of soil in your search.


                                                   Start VideoDemo

Text Version:
Use the “Select by Attribute” feature to determine which borrow sites have the material type suitable for the project at hand:

    1. Select “Selection” in the application toolbar

    2. Left Click “Select by Attributes”

    3. In the “Laye” drop down menu, select the name of the borrow sites layer

    4. Double Click on “Materials” in the “Fields” box

    5. Left Click the “=” button

    6. Select the desired material for the project based on the material available at each of the borrow sites by double clicking the material in the “Unique Values:” window (Note that a query equation is formed as these selections are made such as: “Material” = ‘Crushed Rock’ (Press “Get Unique Values” to show the options if it’s not already shown))

    7. Press “Apply”

(Note: the borrow sites that have the materials selected in the query equation are now highlighted on the map view and in the attribute table)
Close the “Select by attribute” window
If more than one type of material can be used in the project and is listed in the “Unique Values” box, use the “OR” logic key between the expressions. An example equation that would select all borrow sites that have Sand or Crushed Rock available is as follows: “Material” = ‘Crushed Rock’ OR “Material” = = ‘Sand, silt, clay mix’