Example of idempotent seeds:

seeds.rb

# Author:  Ryan McGeary : http://github.com/rmm5t
# License: MIT          : https://rmm5t.mit-license.org/

def restart_sequence(klass)
  seq = [klass.table_name, "id", "seq"].join("_")
  next_id = klass.maximum(:id) + 1
  klass.connection.execute "ALTER SEQUENCE #{seq} RESTART #{next_id}"
end

def load_seed_data(klass, records)
  bar = ProgressBar.create(title: "#{klass} seeds", total: records.length)
  records.each do |record|
    o = klass.find_or_initialize_by(id: record[:id])
    o.update!(record)
    bar.increment
  end
  restart_sequence(klass)
  bar.finish
end

load_seed_data(
  BroadcastType,
  [
    { id: 1, name: "None" },
    { id: 2, name: "AM" },
    { id: 3, name: "FM" },
    { id: 4, name: "FM HD2" },
    { id: 5, name: "FX FEED" },
  ]
)

load_seed_data(
  ContentType,
  [
    { id: 1, name: "Not Defined" },
    { id: 2, name: "Music" },
    { id: 3, name: "News/Talk" },
    { id: 4, name: "Sports" },
  ]
)

load_seed_data(
  Genre,
  [
    { id: 1, name: "Adult Contemporary" },
    { id: 2, name: "Classical" },
    { id: 3, name: "Country" },
    { id: 4, name: "Family" },
    { id: 5, name: "Hip Hop/Urban" },
    { id: 6, name: "Jazz/Blues" },
    { id: 7, name: "News/Talk" },
    { id: 8, name: "Oldies" },
    { id: 9, name: "R&B" },
    { id: 10, name: "Religious" },
    { id: 11, name: "Rock" },
    { id: 12, name: "Spanish" },
    { id: 13, name: "Sports" },
    { id: 14, name: "The Decades" },
    { id: 15, name: "Top 40/Pop" },
    { id: 16, name: "World/Variety" },
    { id: 17, name: "Comedy" },
    { id: 18, name: "NPR" },
  ]
)

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