I need to preserve the shared boundary between polygons but make them a multipart polygon. Dissolve with the multipart polygon checked still dissolves the shared boundary, and only makes one multipart polygon with separate polygons if they are not adjacent and sharing a boundary. Union also dissolves the shared boundary. The attributes for the adjacent polygons are the same. There are 100s of polygons in this layer so I don't want to use editing tools. I am hoping there is a Toolbox tool that will do this. Any help is appreciated. Thank you!
shared boundaries will be removed if dissolving or aggregation by an attribute.
Perhaps you could explain why you want to make multipart shapes? If you have a need to simplify a data structure to minimize duplication of attributes, you can simply keep your attributes separate and use a join when you need to bring attributes back to the geometry
You will have to maintain a geometry file which just contains the individual boundaries if that is paramount.
If you haven't done the dissolve yet, then you can get a statistical summary on an aggregated basis.
Is the aggregation based on ownership? crop type?
Any details would help
Ok that's what I thought, it isn't possible to maintain a shared boundary with multipart polygons. We can manage without it and maintain 2 separate layers if they need to see the original boundaries. Thanks for your help.
Multipart polygons cannot share borders. From the help:
Keep in mind that parts in a multipart polygon are spatially separated. They can touch each other at vertices, but they cannot share edges or overlap.