Removing duplicate rows from a shapefile

Question

I would like to write some c# code to delete duplicate rows from a shapefile stored in a folder.

Can anyone provide me with an example or pointers on the best way to attempt this, please?

Answer 1

To remove duplicate geometry with different fid you may use an algorithm like:

List<IFeature> features = GetAllFeatures(featureClass)
foreach(var feature in features)
{
    string query = "OIDFieldName = feature.OID";
    List<IFeature> queryFeatures = GetFeaturesBasedOnQuery(featureClass, query);
    foreach(var queryFeature in queryFeatures)
    {
         List<IFeature> sameLocationFeatures = GetFeaturesBySameLocation(featureClass, queryFeature.Shape);
         for (int i = 1; i < sameLocationFeatures.Count; i++)
         {
                    sameLocationFeatures[i].Delete();
         }
    }       
}

To get features based on location you may use following code snippent:

    public IFeatureCursor GetFeaturesBySameLocation(IFeatureClass featureClass, IGeometry queryGeometry)
    {
        string shapeFieldName = featureClass.ShapeFieldName;
        ISpatialFilter spatialFilter = new SpatialFilter();
        spatialFilter.Geometry = queryGeometry;
        spatialFilter.SpatialRel = esriSpatialRelEnum.esriSpatialRelIntersects;
        spatialFilter.set_OutputSpatialReference(shapeFieldName, spatialReferance);

        IFeatureCursor featureCursor = featureClass.Search(spatialFilter, false);
        return featureCursor ;
    }

Code snippet for getting all features of a layer:

    public IFeatureCursor GetAllFeatureOfLayer(IFeatureClass featureClass)
    {
        IFeatureCursor featureCursor = featureClass.Search(null, false);
        return featureCursor;
    }

Code snippet for getting features based on query from a layer:

    public IFeatureCursor GetFeaturesBasedOnQuery(IFeatureClass featureClass, string query)
    {
        IQueryFilter queryFilter = new QueryFilterClass();        
        queryFilter.WhereClause = query;
        IFeatureCursor featureCursor = featureClass.Search(queryFilter, false);

        return featureCursor;
    }

Answer 2

I have a python code to delete duplicate geometry..

code snippet:

gp.SelectLayerByAttribute_management(featureverticeshp_Layer, "NEW_SELECTION", gbgquery)    
gp.SelectLayerByLocation_management(featureverticeshp_Layer, "ARE_IDENTICAL_TO", featureverticeshp_Layer, "", "NEW_SELECTION")    
gp.SelectLayerByAttribute_management(featureverticeshp_Layer, "REMOVE_FROM_SELECTION", gbgquery)    
gp.DeleteFeatures_management(featureverticeshp_Layer)

If you want I can provide the entire code (author name: Gerry Gabrisch). (I forgot from where I download it, but works fine with shape file).

Answer 3

Now just convert this shape file tp featureclass and open this using Access and find out those duplicate records and delete those..