Modify Table type object

function extractKeys<T extends object>(obj: T) {
  return Object.keys(obj) as (keyof T)[];
}

type ReturnCrossTable<T extends Table> = {
  [Key in keyof T["_"]["columns"]]: string | SQLWrapper;
} & {
  table: SQL;
};

export function crossDBTable<T extends Table>(
  dbName: string,
  data: T,
): ReturnCrossTable<T> {
  const columns = getTableColumns(data);

  return extractKeys(columns).reduce(
    (acc, key) => {
      return Object.assign(acc, {
        [key]: sql.join([sql.identifier(dbName), columns[key]], sql`.`),
      });
    },
    {
      table: sql.join([sql.identifier(dbName), data], sql`.`),
    },
  ) as ReturnCrossTable<T>;
}