#include #include #include #include #include #include #include namespace DB { namespace ErrorCodes { extern const int NOT_IMPLEMENTED; extern const int NUMBER_OF_ARGUMENTS_DOESNT_MATCH; extern const int ALTER_OF_COLUMN_IS_FORBIDDEN; } void registerStorageNull(StorageFactory & factory) { factory.registerStorage("Null", [](const StorageFactory::Arguments & args) { if (!args.engine_args.empty()) throw Exception(ErrorCodes::NUMBER_OF_ARGUMENTS_DOESNT_MATCH, "Engine {} doesn't support any arguments ({} given)", args.engine_name, args.engine_args.size()); return std::make_shared(args.table_id, args.columns, args.constraints, args.comment); }, { .supports_parallel_insert = true, }); } void StorageNull::checkAlterIsPossible(const AlterCommands & commands, ContextPtr context) const { auto name_deps = getDependentViewsByColumn(context); for (const auto & command : commands) { if (command.type != AlterCommand::Type::ADD_COLUMN && command.type != AlterCommand::Type::MODIFY_COLUMN && command.type != AlterCommand::Type::DROP_COLUMN && command.type != AlterCommand::Type::COMMENT_COLUMN && command.type != AlterCommand::Type::COMMENT_TABLE) throw Exception(ErrorCodes::NOT_IMPLEMENTED, "Alter of type '{}' is not supported by storage {}", command.type, getName()); if (command.type == AlterCommand::DROP_COLUMN && !command.clear) { const auto & deps_mv = name_deps[command.column_name]; if (!deps_mv.empty()) { throw Exception(ErrorCodes::ALTER_OF_COLUMN_IS_FORBIDDEN, "Trying to ALTER DROP column {} which is referenced by materialized view {}", backQuoteIfNeed(command.column_name), toString(deps_mv) ); } } } } void StorageNull::alter(const AlterCommands & params, ContextPtr context, AlterLockHolder &) { auto table_id = getStorageID(); StorageInMemoryMetadata new_metadata = getInMemoryMetadata(); params.apply(new_metadata, context); DatabaseCatalog::instance().getDatabase(table_id.database_name)->alterTable(context, table_id, new_metadata); setInMemoryMetadata(new_metadata); } }