class ActiveRecord::ConnectionAdapters::SchemaCreation

def visit_AlterTable(o)
  sql = +"ALTER TABLE #{quote_table_name(o.name)} "
  sql << o.adds.map { |col| accept col }.join(" ")
  sql << o.foreign_key_adds.map { |fk| visit_AddForeignKey fk }.join(" ")
  sql << o.foreign_key_drops.map { |fk| visit_DropForeignKey fk }.join(" ")
  sql << o.check_constraint_adds.map { |con| visit_AddCheckConstraint con }.join(" ")
  sql << o.check_constraint_drops.map { |con| visit_DropCheckConstraint con }.join(" ")
  sql << o.constraint_drops.map { |con| visit_DropConstraint con }.join(" ")
end