declare
    column_exists exception;
    pragma exception_init (column_exists , -01430);
begin
    execute immediate 'ALTER TABLE ALIAS_CLASSE_SERVICO ADD (CLASSE_CONFORTO_MONITRIP VARCHAR2(30))';
    exception when column_exists then null;
end;
/
declare 
  object_exists exception;
  except_01451  exception;
  except_01442  exception;

  pragma exception_init (object_exists , -01430);
  pragma exception_init (except_01451  , -01451);
  pragma exception_init (except_01442  , -01442);
begin 
  execute immediate 'ALTER TABLE ALIAS_CLASSE_SERVICO ADD EMPRESA_ID NUMBER(7,0) ';
  exception 
    when object_exists  then null;
    when except_01451  then null;
    when except_01442  then null;
end;
/
declare 
  object_exists exception;
  except_01451  exception;
  except_01442  exception;

  pragma exception_init (object_exists , -01430);
  pragma exception_init (except_01451  , -01451);
  pragma exception_init (except_01442  , -01442);
begin 
  execute immediate 'ALTER TABLE ALIAS_CLASSE_SERVICO ADD RUTA_ID NUMBER(7,0) ';
  exception 
    when object_exists  then null;
    when except_01451  then null;
    when except_01442  then null;
end;
/
declare 
  column_exists exception;
  pragma exception_init (column_exists , -01430);
begin 
  execute immediate 'ALTER TABLE ALIAS_CLASSE_SERVICO ADD INDSOMENTEIMPRESSAO NUMBER(1,0)';
  exception when column_exists then null;
end;
/