Simpler way of renaming users

db/post_migrate/20170518200835_rename_users_with_renamed_namespace.rb

@@ -26,15 +26,12 @@ class RenameUsersWithRenamedNamespace < ActiveRecord::Migration
   ]
 
   def up
-    namespace_table = Arel::Table.new('namespaces')
-    users_table = Arel::Table.new('users')
-    matching_path = namespace_table.project(namespace_table[:path])
-                      .join(users_table).on(users_table[:id].eq(namespace_table[:owner_id]))
-                      .where(users_table[:username].not_eq(namespace_table[:path]))
-    path_name = Arel::Nodes::SqlLiteral.new("matching_path.path FROM (#{matching_path.to_sql}) as matching_path")
-
-    update_column_in_batches(:users, :username, path_name) do |table, query|
-      query.where(table[:username].matches_any(DISALLOWED_ROOT_PATHS))
+    DISALLOWED_ROOT_PATHS.each do |path|
+      update_sql = "UPDATE users SET username = namespaces.path "\
+                   "FROM namespaces WHERE namespaces.owner_id = users.id "\
+                   "AND namespaces.type IS NULL "\
+                   "AND users.username ILIKE '#{path}'"
+      connection.execute(update_sql)
     end
   end
 

spec/migrations/rename_users_with_renamed_namespace_spec.rb

@@ -2,8 +2,9 @@ require 'spec_helper'
 require Rails.root.join('db', 'post_migrate', '20170518200835_rename_users_with_renamed_namespace.rb')
 
 describe RenameUsersWithRenamedNamespace, truncate: true do
-  it 'renames a user that had his namespace renamed to the namespace path' do
+  it 'renames a user that had their namespace renamed to the namespace path' do
     other_user = create(:user, username: 'kodingu')
+    other_user1 = create(:user, username: 'api0')
 
     user = create(:user, username: "Users0")
     user.update_attribute(:username, 'Users')
@@ -14,6 +15,8 @@ describe RenameUsersWithRenamedNamespace, truncate: true do
 
     expect(user.reload.username).to eq('Users0')
     expect(user1.reload.username).to eq('import0')
+
     expect(other_user.reload.username).to eq('kodingu')
+    expect(other_user1.reload.username).to eq('api0')
   end
 end