mjhjmtu

I'm trying to iterate through polygons in a feature class to perform zonal statistics on a raster mosaic.

I found inspiration from Iterate through features to use selection as input for ExtractByMask for my code but I get a "RuntimeError: An invalid SQL statement was used. [SELECT OBJECTID, Shape, Group FROM GROUP_RINGS_prj]" message.

Here is the code I use:

import arcpy, datetime

from arcpy import env
from arcpy.sa import *

arcpy.env.overwriteOutput = True

arcpy.CheckOutExtension("Spatial")

env.workspace = "D:/PROJECT.gdb"

aoi_prj = "GROUP_RINGS_prj"
forest_prj = "FOREST_prj"

## Stats by group
with arcpy.da.SearchCursor(aoi_prj, ["OID@", "SHAPE@", "Group"]) as cursor:
 for row in cursor:
 print(datetime.datetime.now().strftime("%Y-%m-%d %H:%M") + ": Processing: " + str(row[2]) + "...")
 zs = ZonalStatisticsAsTable(row[1], "Group", forest_prj, "D:/Projects/Results/ZS_FOREST_" + str(row[0]) + ".dbf", "NODATA", "MEAN")
 row = cursor.next()

It results with:

Traceback (most recent call last):
 File "D:ProjectsScripts.py", line 87, in <module>
 for row in cursor:
RuntimeError: An invalid SQL statement was used. [SELECT OBJECTID, Shape, Group FROM GROUP_RINGS_prj]

Do I miss something obvious in the code?

Group can't be used as a column name, because it's a reserved keyword.

In fact, when you use ArcCatalog to add a field with that name to a featureclass, it will give an error message: The following field names are invalid: group. I wonder how you managed to create this featureclass?

You cant use a geometry (SHAPE@) as in_zone_data to zonal statistics, it should be a feature layer or raster layer. Try creating a feature layer using the objectid of each row instead and use feature layer as input:

with arcpy.da.SearchCursor(aoi_prj, ["OID@", "Group"]) as cursor:
 for row in cursor:
 print(datetime.datetime.now().strftime("%Y-%m-%d %H:%M") + ": Processing: " + str(row[2]) + "...")
 sql = """0=1""".format(arcpy.AddFieldDelimiters(arcpy.Describe(aoi_prj).OIDFieldname),row[0])
 arcpy.MakeFeatureLayer_management(in_features=aoi_prj, out_layer='templyr', where_clause=sql)
 zs = ZonalStatisticsAsTable('templyr', "Group", forest_prj, "D:/Projects/Results/ZS_FOREST_" + str(row[0]) + ".dbf", "NODATA", "MEAN")

This line will probably make you miss every other row. To iterate over each row remove it:

row = cursor.next()