Add an isbn attribute to the MarcRecord class and add the MARC 020 or…

… to it.

app/models/upload.rb

@@ -69,12 +69,19 @@ def extract_marc_record_metadata(file, service)
         marc001: record['001']&.value,
         file_id: file.id,
         upload_id: id,
-        marc: record
+        marc: record,
+        isbn: record_isbn(record)
       )
 
       out.checksum ||= Digest::MD5.hexdigest(record.to_xml.to_s)
 
       yield out
     end
   end
+
+  def record_isbn(record)
+    marc020 = record['020'] || {}
+
+    (marc020['a'] || marc020['z'])&.[](/^x?\d+/)
+  end
 end

db/migrate/20201120180608_add_isbn_to_marc_record.rb

@@ -0,0 +1,6 @@
+class AddIsbnToMarcRecord < ActiveRecord::Migration[6.0]
+  def change
+    add_column :marc_records, :isbn, :string
+    add_index :marc_records, :isbn
+  end
+end

db/schema.rb

@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 2020_11_19_191233) do
+ActiveRecord::Schema.define(version: 2020_11_20_180608) do
 
   create_table "active_storage_attachments", force: :cascade do |t|
     t.string "name", null: false
@@ -91,8 +91,10 @@
     t.bigint "length"
     t.bigint "index"
     t.string "checksum"
+    t.string "isbn"
     t.index ["file_id", "marc001"], name: "index_marc_records_on_file_id_and_marc001"
     t.index ["file_id"], name: "index_marc_records_on_file_id"
+    t.index ["isbn"], name: "index_marc_records_on_isbn"
     t.index ["upload_id", "marc001"], name: "index_marc_records_on_upload_id_and_marc001"
     t.index ["upload_id"], name: "index_marc_records_on_upload_id"
   end