Transfering vector Style classification into Attribute table in QGIS?

Question

I have a shapefile with a few thousand shapes, each with a specific value. Using Graduated classifcation, I can classify these shapes into ten categories based on value ranges. I'd like to use these 10 categories for statistical calculations. To do this I need to pull these categories into the Attribute table.

Is there a way a that this can be done, without manually doing the classification with From-To values in the the field calculator?

Answer 1

At the moment, I don't think there is an easier method other than creating an expression for the Field Calculator and storing the value ranges in a string field. With 10 categories, it would be a fairly long expression where it could look something like:

CASE
WHEN "fieldName" >= 1 AND "fieldName" < 10 THEN '1.0 - 10.0'
WHEN "fieldName" >= 10 AND "fieldName" < 20 THEN '10.0 - 20.0'
WHEN "fieldName" >= 20 AND "fieldName" < 30 THEN '20.0 - 30.0'
...
WHEN "fieldName" >= 90 AND "fieldName" < 100 THEN '90.0 - 100.0'
ELSE '0'
END