```ruby
class ChangeSpreePriceAmountPrecision < ActiveRecord::Migration
  def change
    change_column :spree_prices, :amount,  :decimal, :precision => 10, :scale => 2
    change_column :spree_line_items, :price,  :decimal, :precision => 10, :scale => 2, :null => false
    change_column :spree_line_items, :cost_price,  :decimal, :precision => 10, :scale => 2
    change_column :spree_variants, :cost_price, :decimal, :precision => 10, :scale => 2
  end
end
```

Drop not null constraint for amount in spree line items
user
```ruby
class ChangeSpreePriceAmountPrecision < ActiveRecord::Migration
  def change
    change_column :spree_prices, :amount,  :decimal, :precision => 10, :scale => 2
    change_column :spree_line_items, :price,  :decimal, :precision => 10, :scale => 2
    change_column :spree_line_items, :cost_price,  :decimal, :precision => 10, :scale => 2
    change_column :spree_variants, :cost_price, :decimal, :precision => 10, :scale => 2
  end
end
```
assistant