if not (Exists (Select Table_name from SysTable where Table_name='SpaCounters')) then
  create table SpaCounters
  (
    InvoiceCounter      integer default 0,
    LastInvoiceOtchet   integer default 0,
    LastDepositOtchet   integer default 0,
    TrueInvoiceNo       integer default 0,
    DepositCounter      integer default 0
  )
end if

GO

IF (EXISTS (select proc_name from sysprocedure where proc_name='SpaGetCounter')) THEN
  Drop function SpaGetCounter;
END IF;

GO

CREATE FUNCTION "DBA"."SpaGetCounter"(in CounterName char(50))
returns integer
begin atomic
  declare @R integer;
  execute immediate 'set @R = isnull((SELECT '||CounterName||' FROM SpaCounters),0)';
  execute immediate 'UPDATE SpaCounters SET '||CounterName||'='||(@R+1);
  return(@R+1)
end