artist versions: convert other_names, url_string to arrays (#3987).

db/migrate/20181114185032_change_strings_to_arrays_on_artist_versions.rb

@@ -0,0 +1,19 @@
+class ChangeStringsToArraysOnArtistVersions < ActiveRecord::Migration[5.2]
+  def up
+    ArtistVersion.without_timeout do
+      change_column :artist_versions, :other_names, "text[]", using: "array_remove(regexp_split_to_array(other_names, '\\s+'), '')", default: "{}"
+
+      change_column :artist_versions, :url_string, "text[]", using: "array_remove(regexp_split_to_array(url_string, '\\s+'), '')", default: "{}"
+      rename_column :artist_versions, :url_string, :urls
+    end
+  end
+
+  def down
+    ArtistVersion.without_timeout do
+      rename_column :artist_versions, :urls, :url_string
+      change_column :artist_versions, :url_string,  "text", using: "array_to_string(url_string,  '\\n')", default: nil
+
+      change_column :artist_versions, :other_names, "text", using: "array_to_string(other_names, ' ')", default: nil
+    end
+  end
+end

db/structure.sql

@@ -726,9 +726,9 @@ CREATE TABLE public.artist_versions (
     updater_id integer NOT NULL,
     updater_ip_addr inet NOT NULL,
     is_active boolean DEFAULT true NOT NULL,
-    other_names text,
+    other_names text[] DEFAULT '{}'::text[],
     group_name character varying,
-    url_string text,
+    urls text[] DEFAULT '{}'::text[],
     is_banned boolean DEFAULT false NOT NULL,
     created_at timestamp without time zone,
     updated_at timestamp without time zone
@@ -7573,6 +7573,7 @@ INSERT INTO "schema_migrations" (version) VALUES
 ('20181108162204'),
 ('20181108205842'),
 ('20181113174914'),
-('20181114180205');
+('20181114180205'),
+('20181114185032');