ALTER TABLE `petition`
  DROP KEY `index_ownerguid_charterguid`,
  CHANGE COLUMN `charterguid` `petitionguid` int(10) unsigned default '0',
  ADD UNIQUE KEY `index_ownerguid_petitionguid` (`ownerguid`,`petitionguid`);
ALTER TABLE `petition_sign`
  DROP PRIMARY KEY,
  CHANGE COLUMN `charterguid` `petitionguid` int(10) unsigned default '0',
  ADD PRIMARY KEY (`petitionguid`,`playerguid`);