create urls

db/migrations/005_create_urls.rb

@@ -0,0 +1,31 @@
+Sequel.migration do
+  up do
+    create_table(:urls) do
+      primary_key :id
+      foreign_key :entity_id, :entities, unique: true
+
+      String :url, unique: true, null: false
+
+      DateTime :created_at, null: false
+      DateTime :modified_at, null: false
+    end
+
+    json = Sequel.sqlite_json_op(:json)
+    href = json.extract("$.href")
+
+    DB[:pinboard]
+      .select_append(href.as(:href))
+      .each do |pin|
+        entity_id = pin.fetch(:entity_id)
+        url = pin.fetch(:href)
+        created_at = modified_at = DateTime.now
+
+        DB[:urls].insert(entity_id:, url:, created_at:, modified_at:)
+      end
+  end
+
+  down do
+    drop_table(:tags)
+    drop_table(:entities_tags)
+  end
+end