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Two methods to find records with duplicate geometries within a single feature class

by Anonymous on ‎03-15-2016 09:23 AM - edited on ‎04-06-2016 11:38 AM by Moderator (983 Views)

Question

How does one find records with duplicate geometries in a single feature class?

Answer

These workflows assume a linear feature class named ROADS with a unique key named ID.

 

Aggregation Method:
Aggregate ROADS to ROADS and count the number of geometry instances then perform an Attribute Query to determine where the count is greater than 1.

Steps:
1) Use the Analysis > Aggregation command to Aggregate to summary features in ROADS from detail features in ROADS using a Spatial Aggregation that aggregates where summary features 'are spatially equal' to detail features. Use the Output tab to setup and create a new functional attribute called GeometryCount that has the defined expression of COUNT(*)

Note: Do not use the default output function name of Count, as it is not supported in Step 2.

2) Use the Analysis > Attribute Query command with the input of the aggregation query from Step1 to find where GeometryCount > 1.

The result of the Attribute Query will be those features that have duplicate geometries (i.e. the GeometryCount is greater than 1.).

 

Spatial Intersection Method:
Perform a Spatial Intersection of ROADS with ROADS followed by an Attribute Query to determine where ID is not equal to ID1.

Steps:
1) Use Analysis > Spatial Intersection to generate intersections of features in ROADS that 'are spatially equal' to features in ROADS.

The Spatial Intersection query result contains all attributes twice, with a number 1 added to the second entry, so far example you will have one attribute named ID and another named ID1.

2) Use the Attribute Query command to select features in the Spatial Intersection Query where ID <> ID1.

 

This attribute query returns instances of duplicate geometry in the ROADS table.

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