@mutatecommand has the form
source |> @mutate(args...). …
args...are executed in order, and the result set of the previous mutation is the source of each current mutation.
However, in the following example, the old values of
a seem to be used.
julia> DataFrame(a=[1,2], b=[0, 3]) |> @mutate(a=_.a/2, b = _.a + _.b) 2x2 query result a │ b ────┼── 0.5 │ 1 1.0 │ 5