-- Add comments to the columns 
comment on column I_SPECIALCHARGESPERCUSTOMER.FREQUENCY
  is '1=per invoice
2=once a week on invoice
3=on statement
4=every direct invoice only
5=per delivered piece
6=every processed delivery note
7=every normal visit
8=every special visit
9=per active wearer per invoice';
-- Create/Recreate check constraints 
alter table I_SPECIALCHARGESPERCUSTOMER
  drop constraint I_CUSTSPECIALCHARGEFREQ;
alter table I_SPECIALCHARGESPERCUSTOMER
  add constraint I_CUSTSPECIALCHARGEFREQ
  check (FREQUENCY between 1 and 9);
