attribute-tableqgisqgis-modeler
I have developed my own model, which processes input vector layer. The final output is vector layer that contains many attribute fields, and of course, also the geometry, but I need a simpler output – geometry and most of those fields are unnecessary.
With this model, how can I get a simple table output with selected attribute fields of the output layer?
In your QGIS modeler, add the Field Calculator algorithm as shown in the image below. I notice in your image that you have "Date" as a parameter name and you also want to use "Date" as a field name. Change the parameter name to another such as "Enter date", don't make it the same name.
In the Field Calculator settings, add "Date" in the Result field name option and you can type or select "Enter Date" from the dropdown menu in the Formula option:
If you use Date as the Field type (as in the image), the format you enter must be 'YYYY-MM-DD'(note the single quotes!). If you want to use another format then use String as the Field type (remember to increase the Field length), you can then enter anything you like in whatever format you like.
Use the normal Field Calculator and in the Formula option, select Pre-calculated Value. Then use the expression:
'(' || @a || ' + ' || @b || ') / 2'
where the parameters @a and @b are the fields you assign when running the model. This is read by the field calculator as a string version of:
(A + B) / 2
Best Answer
You could use the GDAL Ogr 2 Ogr algorithm to convert the vector file to a CSV, and then run that CSV through the QGIS algorithm "Delete column" to remove the geometry column (and any others you don't need). I haven't tried it, but it might work.
[Edit] Okey, did a quick test. The GDAL convert to CSV works fine in model builder, but it seems like the QGIS delete column operation can't handle non spatial data, so you need to remove your columns with that before you convert it to CSV. However, the convert to CSV operation does not create a geometry column in the CSV file, so that shouldn't be a problem.