[web2py] How do you define a column name on summed field (i.e. how to do the equivalent of an sql 'select ..... as colname'

[Paul]

In the dal I'm selecting two summed fields and adding them together,
the column name in the set object ends up being called
'(SUM(t_appointment.miles_to) + SUM(t_appointment.miles_from))', how
would I define the dal query to get an better column name (e.g.
total_miles) ?

Current query is:


def mileage():
    mysum = db.t_appointment.miles_to.sum()
+db.t_appointment.miles_from.sum()
    groupyyyymm = db.t_appointment.f_start_time.year()|
db.t_appointment.f_start_time.month()
    rows = db().select(
        mysum,
        db.t_appointment.f_start_time.year(),
        db.t_appointment.f_start_time.month(),
    groupby=groupyyyymm)

    return dict(rows=rows, sql = db._lastsql)


Thanks,

Paul