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I have joined corresponding Local Enterprise Partnerships table data into a polygon shapefile containing UK Local Authorities.

enter image description here

How do I Dissolve or Merge the the Local Authorities polygons by LEP_NAME as shown in the screenshot?

Ideally, I would like to retain the Local Authority attributes with the resultant merged polygons. I have zero scripting knowledge so am looking for a tool based solution. Any help or pointers much appreciated.

enter image description here

Additional Note: When attempting to use the dissolve tool the LEP_NAME field is not available as shown above. The LEP attribute data was created in Excel, saved as CSV format and joined to the Local Authority polygon shapefile. There are duplicate IDENTIFI0 fields as shown in the other screenshot - could this be the root of the issue?

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use vector ->geoprocessing tools --> dissolve:

select shapefile and field (LEP_NAME in your case), choose name for new shapefile and you are done enter image description here

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    Thanks for your suggestion Kurt - I tried doing this and the problem is that the field I wish to select is not in the Dissolve pull down menu: – Jeremy Oct 6 '13 at 16:01
  • Please see the additional edit to my original post. – Jeremy Oct 6 '13 at 16:09
  • strange, how did you "Join" it ? maybe a look at this tutorial helps: qgis.spatialthoughts.com/2012/03/… – Kurt Oct 6 '13 at 18:36
  • Hi Kurt, that was the exact tutorial I used to create the Join. I've tried a couple more times using the CSVT file method and by renaming the Join field to be unique. Still no luck. It appears that the "joined" fields from the CSV file to the SHP file are missing from the pulldown. Is there anything else I am missing? – Jeremy Oct 6 '13 at 22:57
  • Anyone? Still no solution. – Jeremy Oct 9 '13 at 23:20
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I had the same issue. I solved it by saving the post-join shape file down and then dissolving after that. Make sure you have the correct vector layer selected in the dissolve prompt to get your new fields.

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regarding this issue I found that fields does not appears in the drop-down menu when the field "type" is float.

It varies according to the software used, but copying the values to a text field may usually work.

Hope this helps to somebody else.

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