Greetings, I am running into a small problem. SearchCursor documentation states that search cursors can handle multiple field_names yet the below script only returns the first field name explicitly stated in the field_names parameter of the search cursor. If I use an asterisk, it returns the first field name in the list. I need it to return the location_id and lat and long attributes respectively from the view I am querying. Is it possible for a searchcursor to return more than one column / field?
#Explicitly defined object IDs known to be conflated in conflation data model
objectIDList =(55555,44444)#small test#gets distinct location_idsdefgetUniqueLocIDs():
tableRegistry = os.path.join(conn,"myView")
fields =['objectid','location_id','latitude','longitude']
whereExp ="objectid IN {0}".format(objectIDList)
uniqueLocIDs = list(set("{0}".format(row[0])for row in arcpy.da.SearchCursor(tableRegistry,['location_id','latitude'], whereExp)))return list(uniqueLocIDs)print(getUniqueLocIDs())
Returns exactly what I wanted it to without having to do a second pass with a separate search cursor to pull in the attributes. For context, there are two object IDs (non-normalized) that match on a conflated location_id I am returning (object IDs below are anonymized) but I only want one location_id (normalized) and the associated set of lat long coords returned:
Your problem lies in Line #8. Instead of troubleshooting the line as written, what are you trying to achieve with that line? You are creating a list from a set, so it appears you are looking for a list of unique items, correct? If so, what defines uniqueness, location_id, latitude, or both?
End state is to retrieve location_id, lat and long by passing in a list of objectIDs but there exists a 1:M rel between location_ids and object ids (one location id can match to multiple objectIDs) in this non-normalized view I am querying. My result needs to be normalized so while I am using object id to match on to resolve distinct location_id keys, I don't necessarily need objectID in my result set. This leads me to believe that maybe I need to retrieve the normalized key structure as first pass to establish the normalized relational framework or key structure which the block of code I provided does do when just passing object_id in as the field param, and then query for my attributes using that returned key or keys in a second pass with another search cursor, but before I get to that point, I just wanted to figure out why only one column in fields() returns, regardless of whether I provide an explicit list, use an asterisk (all) or pass in 'fields' as the param. It just returns the first column of whatever is passed in as a param regardless of which method I use.
I just wanted to figure out why only one column in fields() returns, regardless of whether I provide an explicit list, use an asterisk (all) or pass in 'fields' as the param.
Your answer is:
"{0}".format(row[0])
The search cursor is returning everything you are asking, you are ignoring everything but the first column.
