Testing whether at table is joined

Question

Hi,
Does anybody know how to see whether a feature layer or table view already contain a join, and if so how to get the name of the join table?

The problem arises from the fact that :
  - arcpy.AddField_management(...) returns an error if the feature class or table is joined and 
  - arcpy.RemoveJoin_mangement() also returns an error if there no join !

There seems only to be tools like arcpy.AddJoin_management and arcpy.RemoveJoin_management

I miss:
a) arcpy.RemoveAllJoins_management

b) a TableView property hasJoin

regards

Michael

FrédéricPRALLY · Answer

Hi,

Maybe try this GP tool: Get joined table properties using geoprocessing tool.

Have fun,

Fred

MichaelStjernholm · Answer

Hi Logan

I don't have a problem of getting my error message as I use ArcGIS10 and immideately get the error thrown in my processing window !

I was considering to solve the issue by grabbing the list of fields and check whether any of the fieldname.split(".) would result in 2 parts of which the first would be the Join table!

regards,

Michael

LoganPugh · Answer

That brings up an interesting point. How do you get the result object from a GP tool that is throwing an error? The result variable in result = gp.RemoveJoin_management("layerName", "fakeJoinName") never gets assigned because Python has to do something with the error it throws.

According to this geoprocessing blog post, you basically can't, unless running it as a GP service on ArcGIS Server.

As an aside, the table name used in the join will be in the error message if you use a nonexistent join name, so you could parse the error message for the table name.

Also I don't see anything new in 10 that helps with this. Maybe take a look at running ArcObjects under Python:
http://gis.stackexchange.com/questions/80/how-do-i-access-arcobjects-from-python
http://gis.stackexchange.com/questions/5017/python-comtypes-and-arcobjects-error-creating-approt-object/5082#5082