I work with this polygon and I try to use the vector tool "Singleparts to Multipart" in order to expload the layer to multipart, so I can select each part seperatly.

I don't care if the features in the attribute table has the same value. All I want is exploded layer:

enter image description here enter image description here

and I get this error:

enter image description here enter image description here

"At Least two features must contain the same attribute value"

I read Producing singlepart featureclass with unique IDs for each spatially non-connected polygon? ,but didn't get an answer

  • Function is trying to find polygons which have the same "myid" value and combine them into multipolygon. Feels like a bug to use term "Unique ID field" in the UI. It might rather be called as "grouping field". If you want to combine all polygons into one multipolygon add a new attribute and fill it with same values. Depending on your use case the dissolve tool may also be usable gis.stackexchange.com/questions/123722/….
    – user30184
    Nov 24, 2016 at 22:03
  • i want to create a lot of features and not create one single feature.
    – newGIS
    Nov 24, 2016 at 22:23
  • 2
    Does it mean Multipart to singleparts?
    – Kazuhito
    Nov 25, 2016 at 0:06
  • i think this is the tool i need
    – newGIS
    Nov 27, 2016 at 6:45

2 Answers 2


You are using the wrong tool. If you want o "explode" multipart features so that you can edit them separately, then you must use the "multipart to single part tool" or use the Multipart Split Plugin.

  • this tool only create temporary layer , but in the attribute table there only one row instead of two rows
    – newGIS
    Nov 27, 2016 at 6:33
  • @newGIS Could you expound a little more on what was the problem? With all due respect, I feel there is small misunderstanding about the tool's behavior. It's advantage and how-to can be found here (direct link) or through the repository page in the answer.
    – Kazuhito
    Nov 27, 2016 at 11:22

The answer is in the error comment: "At Least two features must contain the same attribute value". For example, if it is used the FID field in the "Singlepart to multipart" tool, for shapefile of next image, I got "Invalid unique ID field".

enter image description here

On the other hand, when the "values" field was used, the shapefile named "Multipart" was produced without any problem.

enter image description here

It can be observed that the attributes table of Multipart shapefile has only one record because "value" field has only one value: 15.

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