I'm having trouble with the SelectLayerByAttribute_management() tool. Although it produces no errors or whatsoever, I get an empty selection.This is the code I am using in my standalone script. I've run it down to the part that's causing trouble and added lots of checks import arcpy database = 'D:/Menno/openhabitat/Keillour/HabitatSDM/Habitats.gdb' fc = database + '/SurveyData/HabitatSiteArea' subs = ['504S34','504S35'] sql = """ "PolygonNo" = '%s' """ lyr = 'lyr' # create empty layer to add features to arcpy.MakeFeatureLayer_management(fc,lyr,sql % '') print 'layer exists:', arcpy.Exists(lyr) print 'features in lyr:', arcpy.GetCount_management('lyr').getOutput(0) print 'featureclass exists:', arcpy.Exists(fc) print 'features in feature class:', arcpy.GetCount_management(fc).getOutput(0) l = arcpy.ListFields(fc) m = [] for a in l: m = m + [a.name] print 'field exists in featureclass:', 'PolygonNo' in m # loop along PolygonNos and add each feature to the selection layer for f in subs: print 'PolygonNo:', f print 'Sql:', sql % f arcpy.SelectLayerByAttribute_management(lyr,'ADD_TO_SELECTION', sql % f) print 'Features in lyr after select:', arcpy.GetCount_management(lyr).getOutput(0) ##arcpy.DeleteFeatures_management(lyr) print 'End'This evaluates to:layer exists: True features in lyr: 0 featureclass exists: True features in feature class: 60 field exists in featureclass: True PolygonNo: 504S34 Sql: "PolygonNo" = '504S34' Features in lyr after select: 0 PolygonNo: 504S35 Sql: "PolygonNo" = '504S35' Features in lyr after select: 0 End
As you can see, layer exists, feature class exists, field exists, there are features in the featureclass, and on my word, there are also features with the mentioned attributes.Performing a select by attributes from the arcmap menu or arcmap attribute table view, using the exact same sql phrases does result in a selection. Copying the lines one by one to the arccatalog or arcmap script window does not.
