Expression to calculate sum in QGIS Attribute table

Question

There is a shapefile about facilities with columns "country" and "annual production".

I am looking for an expression for a calc field to summarize total production for all countries.

For example: if a country has 5 facilities, I need to sum up each facility for the total production of this country.

Is there some expression to do that?

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Answer 1

To calculate the sum per country, use this expression:

sum("production", group_by:="country")

Replace "production" and "country" with the field names you have.

• GeoEth: Thanks, it works, but "country" does not need to replace, it must stay like in Your example.
• Babel: Yeah, as long as you use the same names, they can stay like this in the expression, of course

Answer 2

Try the Sum function:

 sum("annual production","country")

I feel this should also work with the aggregate function:

 aggregate('[[your layer name]]',sum,"annual production","country"=@parent)

• Mayo: I think there are some errors in the second expression, take a look to the aggregate documentation. The correct expression is. aggregate('[[your layer name]]', 'sum', "annual production", "country"=attribute(@parent, 'country'))
• GeoEth: To Hjall: no, doesn't work.