topic Re: Problems using the where clause with searchcursor method in Python Questions

Problems using the where clause with searchcursor method

KevinCressy — Wed, 02 Mar 2011 05:25:27 GMT

Hello all,

I am using ArcGIS Desktop 10.0 and I am trying to write a script in python.

I am having problems with the where clause in the searchcursor method.

Basically I have a CAD file and would like to identify from the CAD file all of the Annotations that have been flagged with a ??????? question mark.

So if I have the following list of Annotations in the Text filed of the Annotation CAD feature class, I would like to pull out the 3rd 5th and 6th rows using search cursor:

33334508
33304576
?97464800
64538300
?74537390
?64849300

I have managed to get the where clause in the search cursor to identify individual records but it keeps failing. I have attached an example of the CAD file and also the script.

I believe that the problem may be that the ???question mark??? is confusing the where clause. I have tried to escape the non standard characters and also writing the where clause as a variable but do not seem to be getting anywhere.

If anyone could help it would be really appreciated, I copy my script below......

Regards,

Kevin

import arcpy
from arcpy import env

env.workspace = r"C:\CADfile.dwg"

#This does not work: cur = arcpy.SearchCursor("Annotation",'LEFT("Text",1)='[\\?]'',"","","")
#This works: cur = arcpy.SearchCursor("Annotation","\"Text\" = \'69570020\'")
#This works: cur = arcpy.SearchCursor("Annotation",'"Text" < \'1\'')

cur = arcpy.SearchCursor("Annotation",'\"Text\" LIKE \'\?\%\'\')

# Iterate through the rows in the cursor
for row in cur:
print "Layer: %s, Parcel: %s" % \
(row.Layer, row.Text)

del cur, row

Re: Problems using the where clause with searchcursor method

AndrewChapkowski — Sat, 11 Dec 2021 07:44:00 GMT

Try not putting the field name in quotes and the like statement should work.

Here is what I did to get it to work:

import arcpy

expression = "Text LIKE '?%'"

cadFile = r"c:\temp\CADfile.dwg\Annotation"

cursor = arcpy.SearchCursor(cadFile, expression)

for row in cursor:
    print row.getValue("Text")

del row, cursor

Result:

>>> 
?69570190
?69570430
?69570440
?69570550
>>>

Re: Problems using the where clause with searchcursor method

KevinCressy — Thu, 03 Mar 2011 15:08:06 GMT

Thats great - thanks it worked!

Re: Problems using the where clause with searchcursor method

GraziaZulian — Fri, 04 Mar 2011 05:07:03 GMT

hi
can you give some examples for using: cursor = arcpy.UpdateCursor(FC, expression)

with: shape files
with: geodatabase (*.gdb) FC
with: geodatabase (*.mdb) FC
with: *dbf tables

I stil have problems in preparing the where_clause for the UpdateCursor and SearchCursor.
I can't understand the syntax.
thanks

Re: Problems using the where clause with searchcursor method

AndrewChapkowski — Fri, 04 Mar 2011 09:23:53 GMT

Hello,

Here are some links that explain the syntax a little better from the web help:
http://help.arcgis.com/en/arcgisdesktop/10.0/help/index.html#//00s500000033000000.htm
and
http://help.arcgis.com/en/arcgisdesktop/10.0/help/index.html#/Building_a_query_expression/00s50000002t000000/

Hope this helps,
Andrew

Re: Problems using the where clause with searchcursor method

LukeBehling — Fri, 29 Jul 2011 15:01:20 GMT

Hello Andrew,
I've reviewed the links you posted over and over, and I still cannot get the UpdateCursor to work with a where clause. I am trying to take a selection and do a find and replace on only that selection. The script runs when done without the where clause; but updates the entire feature class.

# Set environment settings
env.workspace = "H:/PythonMSAG/P1_staging.mdb"

# Set local variables
inFeatures = "Address_Points"

cur3 = arcpy.UpdateCursor(inFeatures, '[CITY_ID]=\'KAUK\'')

RESULTS in this error:
Traceback (most recent call last):
File "H:\PythonMSAG\findreplace1.py", line 72, in <module>
    del cur3, row
NameError: name 'row' is not defined

for row in cur3:
    row.MSAG_NAME = string.replace(row.MSAG_NAME, "FOURTH", "4")
    cur3.updateRow(row)

del cur3, row

Re: Problems using the where clause with searchcursor method

AndrewChapkowski — Sat, 11 Dec 2021 07:44:03 GMT

It looks like you might have an incorrect where statement in your code:
Try this:

where =  "[CITY_ID]=\"KAUK\""
cur3 = arcpy.UpdateCursor(inFeatures, where)

Re: Problems using the where clause with searchcursor method

LukeBehling — Fri, 29 Jul 2011 15:32:31 GMT

It still doesn't work. I've tried a Personal (9.3.1) and File geodatabase (10). It seems like no matter what I put in the where clause, it fails.

Re: Problems using the where clause with searchcursor method

AndrewChapkowski — Fri, 29 Jul 2011 15:48:20 GMT

Can you use the Make Feature Layer against the where clause you are trying to use in arcmap?

The tool can be found in arctoolbox -> data management tools -> Layers and Table Views -> Make Feature Layer

Try copying and pasting that where clause for use of the update cursor.

Also, are you the only person using this dataset? You need to be able to get an exclusive data lock on your datasets.

Re: Problems using the where clause with searchcursor method

LukeBehling — Fri, 29 Jul 2011 18:56:53 GMT

Okay, figured it out, the attribute code was different. KAUK should have been KAUC. WHERE clause was correct.