12. Attribute & Spatial Queries


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The data I use today can be downloaded

HERE

Queries and Selections

Attribute Query (ArcGIS Attribute Query Help):  allows the user to select features in a layer based on the values stored in its attribute table.

Select By Location (ArcGIS Select By Location Help):  allows the user to select features based on their location relative to features in another layer.


Attribute Query: Selection >> Select By Attributes …

selectbyattributes2

  • DOUBLE-click a field >> SINGLE-click an operator >> DOUBLE-click a criteria value if the field is a text type (if numeric, either click a value or type in by hand)
  • Use the “Get Unique Values” button after clicking on the field to get a list of possible values
  • Understand the effect your selection method will have on your selection set
  • Use the LIKE operator to build partial text searches:
    • The % signifies to search for any number of wildcard characters
    • The _ (underscore) signifies to search for only one wildcard character
    • “Owner” Like ‘%ature Conservancy’ will return all combinations ending in “ature Conservancy” (The Nature Conservancy, Nature Conservancy, nature Conservancy, …). However, it will not select “The Nature conservancy”, “Nature Conservancy, The”, etc.
    • “Owner” Like ‘_ature Conservancy’ will return all combinations with one character in front of “ature Conservancy” (ie. Nature Conservancy).
    • The wildcards can be placed anywhere in the query value and they can be combined.

Temporarily saving your query for further processing:

Create a selection layer (right-click on the queried layer >> Selection >> Create Layer From Selected Features).  This adds a new layer at the top of the TOC.  Any changes you make to this selection layer is applied to the original layer so be careful.  Very useful when buffering and selecting by location.

Select by location (spatial selections, spatial queries)

These selections leverage the spatial nature of our GIS data.  As long as your coordinate systems are properly applied and are properly defined, this should be easy!

selectbyloc

This ESRI page thoroughly explains the types of supported spatial queries.  You should familiarize yourself with these selection techniques.