Using arcpy for ArcGIS 10.5.1, I'm joining a feature layer to a table using arcpy.AddJoin_management() with the KEEP_ALL option in order to keep all features whether they have a related record in the joined table or not. However, after running the join, the only features in the layer are those that have a related record in the joined table.

My code is:

    arcpy.MakeFeatureLayer_management(inFeatures, tmpLayer)
    arcpy.MakeTableView_management(joinTable, tmpView, "Classification = '{}'".format(seasonClassification))
    arcpy.AddJoin_management(tmpLayer, inField, tmpView, joinField, join_type="KEEP_ALL")

I know I've had this working as expected in other scripts, but not in this case.

What am I doing wrong? How do I get it to keep all features after the join?

  • I've just found that if I do a 'TableToTable' of the tmpView to a temporary in_memory table and then join to the table, instead of to a table view, it works as expected! Must be some quirk where it cannot do a "KEEP_ALL' on a table view, or perhaps not when the table view has a definition query. Jul 17, 2018 at 2:32

1 Answer 1


I've found that it works as expected when joining to a table, but not when joining to a table view (or at least, not a table view with a definition query - I haven't tested without the query).

So my work around is to use arcpy.TableToTable_conversion() to create a temporary in_memory table from the table view, and join to that instead of joining to the table view itself.

This code is now working fine for me:

arcpy.MakeFeatureLayer_management(inFeatures, tmpLayer)
arcpy.MakeTableView_management(joinTable, tmpView, "Classification = '{}'".format(seasonClassification))
#  Need to use a temporary table for the join, otherwise "KEEP_ALL" fails to keep all when joining to a view (at least in this case)
arcpy.TableToTable_conversion(tmpView, os.path.dirname(tmpTable), os.path.basename(tmpTable))
arcpy.AddJoin_management(tmpLayer, inField, tmpTable, joinField, join_type="KEEP_ALL")

I'm not sure if this is a known limitation, or a bug. I've been unable to find any documentation for this behaviour.

  • This is another example of 'things I hate about ArcGIS". Functions that "should work" and very often "do work" on another computer/dataset/day/etc... refuse to work as expected and then you're forced to come up a funky workaround.
    – user2856
    Jul 17, 2018 at 3:24
  • Yup. If I had a dollar for every time I had to come up with a work around for weird ArcGIS behaviour... Jul 17, 2018 at 3:35

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