refactor out getting old column comment
refactor out getting old column comment

BenMorel/dbal,doctrine/dbal,lcobucci/dbal,lcobucci/dbal,mikeSimonson/dbal,drieschel/dbal,doctrine/dbal,drieschel/dbal,deeky666/dbal,BenMorel/dbal,mikeSimonson/dbal,deeky666/dbal