Allow `truncate` for SQLite3 adapter and add `rails db:seed:replant` (#34779)

* Add `ActiveRecord::Base.connection.truncate` for SQLite3 adapter.

SQLite doesn't support `TRUNCATE TABLE`, but SQLite3 adapter can support
`ActiveRecord::Base.connection.truncate` by using `DELETE FROM`.

`DELETE` without `WHERE` uses "The Truncate Optimization",
see https://www.sqlite.org/lang_delete.html.

* Add `rails db:seed:replant` that truncates database tables and loads the seeds

Closes #34765

1 files changed, 18 insertions, 0 deletions

diff --git a/activerecord/lib/active_record/tasks/database_tasks.rb b/activerecord/lib/active_record/tasks/database_tasks.rb
index 27e401a756..ef02ca8190 100644
--- a/activerecord/lib/active_record/tasks/database_tasks.rb
+++ b/activerecord/lib/active_record/tasks/database_tasks.rb
@@ -182,6 +182,24 @@ module ActiveRecord
         }
       end
 
+      def truncate_tables(configuration)
+        ActiveRecord::Base.connected_to(database: { truncation: configuration }) do
+          table_names = ActiveRecord::Base.connection.tables
+          internal_table_names = [
+            ActiveRecord::Base.schema_migrations_table_name,
+            ActiveRecord::Base.internal_metadata_table_name
+          ]
+
+          class_for_adapter(configuration["adapter"]).new(configuration).truncate_tables(*table_names.without(*internal_table_names))
+        end
+      end
+
+      def truncate_all(environment = env)
+        ActiveRecord::Base.configurations.configs_for(env_name: environment).each do |db_config|
+          truncate_tables db_config.config
+        end
+      end
+
       def migrate
         check_target_version