How to delete records from multiple, similar feature classes by attribute values using an SQL statement?

Question

I have several hundred geodatabase feature classes which all have the exact same fields. I need to go through each of those feature classes and delete any records which match an SQL query (the same SQL query can be applied to all the feature classes). Alternatively, I could export them all to new feature classes, keeping the records I want. In ArcCatalog I can export them singly using an SQL query to specify which records get exported, but the SQL statement option isn't available when you want to export multiple layers simultaneously (using "Feature Class to Geodatabase (multiple)").

Answer 1

One way to automate the processing of this would be with Python by working through a list of the feature classes, and the using an updatecursor/deleteRow statement to delete the unneeded records.

import arcpy

workspace = r"c:\yourworkspace\yourgeodatabase.gdb"  #assuming file geodatabase
arcpy.env.workspace = workspace

#Part 1 -- create list of feature classes in your geodatabase...
#assuming all featureclasses within the geodatabase are of interest for the query -- otherwise specify a wildcard below

featureclasslist = arcpy.ListFeatureClasses()

#now run a loop on feature classes in the list
for featureclass in featureclasslist:


 #Part 2 -- deleting the records specified in your sql query. There are two approaches:

 # option1:
    your_query = " \"yourfield\" = 'your_value' "  #enter your sql query here

    rows = arcpy.UpdateCursor(featureclass, your_query)
    for row in rows:
        rows.deleteRow(row)

    # or option 2

    rows = arcpy.UpdateCursor(featureclass)
    for row in rows:
        if row.getValue("Yourfield") == 'your_value':
            rows.deleteRow(row)

More here on listing featureclasses: http://help.arcgis.com/en/arcgisdesktop/10.0/help/index.html#//000v0000001n000000

and on the updatecursor/deleteRow statement: http://help.arcgis.com/en/arcgisdesktop/10.0/help/index.html#//002z0000001q000000