query example

.ex

  defp planting_operations_only do
        from operation in Operation,
      where: operation.operation_type == "planting",
    preload: :variety
  end
  
    def crop_plan_preloads(query) do
        from q in query,
      preload: :crop,
      preload: :fields,
      preload: [operations: ^planting_operations_only]
  end