sql - Rails query the last of each type -

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i using sti , have table widget bunch of other subclasses inherit using sti. want query gets last created of each object uniq type.

i have predefined array of types want lets say:

types = ["type1", "type2", "type3"]

so query like: (this doesnt work)

widget.where(type: types).uniq.reverse

my goal last of each object matches 1 of types..

not 100% sure, might work (untested):

ids = thing.where(type: types).group(:type).maximum(:id).values last_per_type = thing.find(ids)

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