```ruby
class AddVariantToJournalEntryItems < ActiveRecord::Migration
  def change
    add_column :journal_entry_items, :variant_id, :integer
  end
end
```

Add historic resumption for jei variant
user
```ruby
class AddVariantToJournalEntryItems < ActiveRecord::Migration
  def up
    add_column :journal_entry_items, :variant_id, :integer

    #  historic resumption
    execute 'UPDATE journal_entry_items AS jei' \
            ' SET variant_id = pi.variant_id' \
            ' FROM' \
            '   journal_entries AS je' \
            '   JOIN purchases AS p ON p.journal_entry_id = je.id' \
            '   JOIN purchase_items AS pi ON pi.purchase_id = p.id' \
            ' WHERE je.id = jei.entry_id' \


    execute 'UPDATE journal_entry_items AS jei' \
            ' SET variant_id = si.variant_id' \
            '  FROM' \
            '    journal_entries AS je' \
            '    JOIN sales AS s ON s.journal_entry_id = je.id' \
            '    JOIN sale_items AS si ON si.sale_id = s.id' \
            '  WHERE je.id = jei.entry_id' \


    # execute 'UPDATE journal_entry_items AS jei' \
    #         " SET variant_id = ii.variant_id" \
    #         ' FROM' \
    #         '    journal_entries AS je' \
    #         '    JOIN inventories AS i ON i.journal_entry_id = je.id' \
    #         '    JOIN inventory_items AS ii ON ii.inventory_id = i.id' \
    #         ' WHERE je.id = jei.entry_id' \

    execute 'UPDATE journal_entry_items AS jei' \
            ' SET variant_id = pi.variant_id' \
            ' FROM' \
            '    journal_entries AS je' \
            '    JOIN parcels AS p ON p.journal_entry_id = je.id' \
            '    JOIN parcel_items AS pi ON pi.parcel_id = p.id' \
            ' WHERE je.id = jei.entry_id' \
  end

  def down; end
end
```
assistant