You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: 20201028212440_add_forgotten_column.go
    path of file: ./repos/dendrite/roomserver/storage/sqlite3/deltas
    
    the code of the file until where you have to start completion: // Copyright 2020 The Matrix.org Foundation C.I.C.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the L
    
func UpAddForgottenColumn(ctx context.Context, tx *sql.Tx) error {
	_, err := tx.ExecContext(ctx, `	ALTER TABLE roomserver_membership RENAME TO roomserver_membership_tmp;
CREATE TABLE IF NOT EXISTS roomserver_membership (
		room_nid INTEGER NOT NULL,
		target_nid INTEGER NOT NULL,
		sender_nid INTEGER NOT NULL DEFAULT 0,
		membership_nid INTEGER NOT NULL DEFAULT 1,
		event_nid INTEGER NOT NULL DEFAULT 0,
		target_local BOOLEAN NOT NULL DEFAULT false,
		forgotten BOOLEAN NOT NULL DEFAULT false,
		UNIQUE (room_nid, target_nid)
	);
INSERT
    INTO roomserver_membership (
      room_nid, target_nid, sender_nid, membership_nid, event_nid, target_local
    ) SELECT
        room_nid, target_nid, sender_nid, membership_nid, event_nid, target_local
    FROM roomserver_membership_tmp
;
DROP TABLE roomserver_membership_tmp;`)
	if err != nil {
		return fmt.Errorf("failed to execute upgrade: %w", err)
	}
	return nil
}