source 'https://rubygems.org'
gem 'better_batch-active_record'

class MyModel < ApplicationModel
  extend BetterBatch::ActiveRecord::Model
end

# all rows must have the same keys
data = [
  { unique_field: 1, ... },
  { unique_field: 2, ... },
  { unique_field: 3, ... },
  ...
]

# you can have the library mutate your input data directly
MyModel.better_batch.set_upserted_pk(data, unique_by: :unique_field)
=> nil
data
=> [ { id: 1, unique_field: ... }, ...]

# if you need to do something a little more involved
# except: will prevent extraneous fields from going to the database
MyModel.better_batch.with_upserted_pk(data, except: :child_records, unique_by: :unique_field) do |data, pk|
  data[:id] = id
  data[:child_records].each do |child_record|
    child_record[:parent_id] = id
  end
end

# you can return fields that you did not modify
MyModel.better_batch.upsert(data, unique_by: :unique_field, returning: [:id, :unmodified_field])
=> [{ id: 1, unmodified_field: 'unmodified data' }, ...]

# you can return all fields
MyModel.better_batch.upsert(data, unique_by: :unique_field, returning: '*')
=> [{ id: 1, unmodified_field: 'unmodified data', another_field: ... }, ...]

# you can use select/selected variations if you don't want any inserts/updates
# missing rows will have a nil primary key
MyModel.better_batch.set_selected_pk(data, unique_by: :unique_field)
=> nil
data
=> [ { id: 1, unique_field: ... }, ...]

MyModel.better_batch.with_selected_pk(data, unique_by: :unique_field) do |data, pk|
  # can be used similarly to the upsert example above
end

# maybe you don't need any results at all
MyModel.better_batch.upsert(data, unique_by: :unique_field)
=> nil

# or maybe something as simple as this is useful to you
MyModel.better_batch.upsert(data, unique_by: :unique_field, returning: :id)
=> [1, 2, 3, ...]

# you can get back instantiated models with all fields
# including the primary key
MyModel.better_batch.upsert(data, unique_by: :unique_field, return_type: :model)
=> [*models]

MyModel.better_batch.select(data, unique_by: :unique_field, return_type: :model)
=> [*models]

# you can similarly get models with only some populated fields
MyModel.better_batch.upsert(data, unique_by: :unique_field, return_type: :model, returning: [:id, :field1])
=> [*models_with_only_id_and_field1_populated]