Unable to read data from Query Layer

deleted-user-Ohz6rwd1kavx

Hi,

I'm unable to use Python/Geoprocessing to read data from an ESRI Query Layer. How can I make this work?

I've tried two things:
1) Use Make Feature Layer to read from .lyr

Reference: http://forums.arcgis.com/threads/584-beta-10-system-tool-for-extracting-query-layer-data-to-file-gdb

Code explained: Works for .lyr based on layer (data source is sde spatial view which arcgis sees as a feature class). Does not work for .lyr based on query layer (data source is sde view which arcgis sees as a table).

# Import system modules
import sys, string, os, arcpy

arcpy.AddMessage("start script....")

#lyr = "C:\Projects\BranchMapping\dev\src\GP_Tasks\ppOwner.lyr"
lyr = "C:\Projects\BranchMapping\dev\src\GP_Tasks\BRANCHES.lyr"

#qry = "KeyInstn = 4001616" # D
qry = "KeyInstn = 4019974" # VABK

arcpy.AddMessage("Making feature layer....")
arcpy.MakeFeatureLayer_management(lyr, "lyr", qry)

arcpy.AddMessage("Getting count....")
result = arcpy.GetCount_management("lyr")

count = int(result.getOutput(0))
arcpy.AddMessage(str(count))

2) MakeQueryTable

Reference: http://forums.arcgis.com/threads/25496-Query-Layer?highlight=query+layer+geoprocessing+python

Opening the tool I browse to the sde view. Afterwards I get this error: ERROR 000793
Invalid data element type ERROR 000840: The value is not a Raster Layer.

I read the doc, but I don't understand. Can I use this tool to create a layer from a "query layer" table data source (i.e. same data source that I can use to create a Query Layer in ArcMap).

Does ESRI have a way to use PY to read data from a Query Layer data source?

Thanks,

-Cory

JohnPenney

Hi,

What version of Arc are you using?

I did get this working based on your example. There may have been some small syntax errors in your code.
Try writing your lyr and qry like this:
[HTML]
#lyr = "C:\Projects\BranchMapping\dev\src\GP_Tasks\ppOwner.lyr"
lyr = r"C:\Projects\BranchMapping\dev\src\GP_Tasks\BRANCHES.lyr"

#qry = "KeyInstn = 4001616" # D
qry = "\"KeyInstn\" = 4001616" # VABK
[/HTML]

There is a little more info on correct syntax within a where clause for Python here:
http://resources.arcgis.com/en/help/main/10.1/index.html#//001700000071000000

And the error that you are receiving when trying to use "SelectLayerByAttribute" may be fixed by using "MakeFeatureLayer" first which works as input for the Select Layer by Attribute tool. So basically something like this:
[HTML]

# Import system modules
import sys, string, os, arcpy

#lyr = "C:\Projects\BranchMapping\dev\src\GP_Tasks\ppOwner.lyr"
lyr = r"C:\Projects\BranchMapping\dev\src\GP_Tasks\BRANCHES.lyr"

#qry = "KeyInstn = 4001616" # D
qry = "\"KeyInstn\" = 4001616" # VABK

# You do need to make feature layer to use as input select layer by attribute
arcpy.MakeFeatureLayer_management(lyr,"lyr")

arcpy.SelectLayerByAttribute_management("lyr", "NEW_SELECTION", qry)

result = arcpy.GetCount_management("lyr")
count = int(result.getOutput(0))
arcpy.AddMessage(str(count))
[/HTML]

I hope that helps!