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I have polygons shapefile in which some of the polygons have same attributes as seen below:-

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In QGIS, how do I merge the polygons having the same attributes into one polygon?

In other words, am looking for a way to merger polygons/attribute of the same layer, that is similar way of merging vector layers found at: Vector >> Data Management Tools >> Merge Vector Layers

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3 Answers 3

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If I understand your question right you can use the 'Dissolve Tool' in 'Geoporcessing Tools' in QGIS.

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"Bayelsa Wards" would be your 'Input vector layer' and "Ward code" the 'Dissolve field'.

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  • In QGIS 2.16 on windows you will have a 'Dissolve all" check box which you will need to turn off. Then select the dissolve field as in @poellinf 's answer
    – Martin Hügi
    Mar 25, 2017 at 9:55
  • @MartinHügi thank you for the additional information. To complete my answer, I'm using QGIS 2.18.0 on MacOS 10.11.6
    – blabbath
    Mar 25, 2017 at 10:32
  • Ok, thanks for your time. However, @iant's reply below did exactly what I wanted (I wanted multiple polygons to share the same attribute). So "Singleparts to Multiparts" is what I wanted not "Dissolve".
    – userPyGeo
    Mar 26, 2017 at 16:07
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You can use the Singleparts to Multiparts in the Vector Geometry tools section of the processing toolbox to do this. It will prompt you for the input layer (from a dropdown list) and the Unique ID field (Ward Code) and you can specify an output file name.

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  • Has this been renamed 'Promote to Multipart'?
    – nr_aus
    Jun 25, 2021 at 2:54
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    Additionally - The OP has accepted the above as the correct answer which - I believe will only work when all the attributes are of the same value. However, if the example is that there are two records with different attributes that need to be merged, the correct answer is to use DISSOLVE tool.
    – nr_aus
    Jun 25, 2021 at 3:06
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You can merge the field with the selection tool and the merge polygons, however you must select the fields from the attribute table.

the merge tool 3rd red scissors

table attribute select the yellow pencil to edit the shapefile table attributes >select the IDs you want to merge by shift button Click the merge button on the main interface

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