I want to dissolve the layer based on two or more fields through "Processing modeler".

How to set and where to set those fields? When I use "Dissolve" tool separately I can choose fields that I want, but not in this case.

I am using QGIS 3.10.

example This is my table. I like to dissolve with fields: "SP" and "PJ" enter image description here


You can set the columns right there in the dialogue, you simply have to know how exactly they are named - and if you want to reuse the model, the columns have to stay the same, or you'd have to alter the model every time.

enter image description here

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  • I already tried with my fields, but I don't know how to write. When I write my fields like: state, city, after processing I get one column with those fields together. – nagib Nov 29 '19 at 9:12
  • There are no fields in the dropdown list?. – nagib Nov 29 '19 at 9:19
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    How should the model know, how the columns of the data, which is to be processed anytime in the future, are called? Please state how exactly you wrote your column names into this field. – Erik Nov 29 '19 at 9:25
  • I supplemented the question. I want to dissolve with "SP" and "PJ". I wrote exactly this: sp, pj and nothing happened – nagib Nov 29 '19 at 10:45
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    @nagib - Use the Vector Field input parameter in your model and connect this to your input layer (enable the Accept multiple fields option). Then in the Dissolve tool, connect the dissolve field to the Vector Field parameter and away you go. – Joseph Nov 29 '19 at 10:52

I was able to solve the problem. Thank You Joseph. The problem was with GDAL Dissolve tool. I used QGIS dissolve tool, and everything work fine. enter image description here

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  • Note that it should also work with GDAL's Dissolve tool. – Joseph Nov 29 '19 at 11:24
  • Not in my case. The result with GDAL is everything is summarised in one field – nagib Nov 29 '19 at 11:28

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