Selecting the most recent entries from a table in Arc

Question

I have a point shape file that has many event occurances stored for ever point. I am trying to select the most recent event for every point. Is there a way to do this through the "Select by Attributes" in Arc?

Answer 1

If you have a identifier that the duplicate points share, you've got it made with a simple SQL query. Just write a sql statement that groups by duplicate point identifier. You could pull your shapefile into a personal geodatabase (*.mdb) with ArcCatalog, then open it with MS Access. Or pull it into PostgreSQL.

 FID | Duplicate_ID | Surname | Created
------------------------------------------
 1   |  1           | Smith   | 2008-01-01
 2   |  1           | Windsor | 2008-02-01
 3   |  2           | Thorn   | 2008-01-05
 4   |  2           | Baker   | 2008-03-01
 5   |  3           | Sykes   | 2008-01-20

SELECT Duplicate_ID, Forename, Surname
FROM mytable AS t
WHERE Created =
   ( SELECT MAX(Created)
     FROM mytable
     WHERE Duplicate_ID = t.Duplicate_ID )

If you don't have an identifier that indicates duplicates, you're screwed.. Actually you'll just need to do some intersection work with the data first.

"Generate Near Table - Determines the distances from each feature in the input features to one or more nearby features in the near features, within the search radius. The results are recorded in the output table."

"Both the Input Features and Near Features can be the same dataset. In that case when the input and near features are the same record, that result will be skipped so as not to report that each feature is 0 units from itself."

arcpy.GenerateNearTable_analysis

http://help.arcgis.com/en/arcgisdesktop/10.0/help/index.html#/Generate_Near_Table/00080000001n000000/