declare
    column_exists exception;
    pragma exception_init (column_exists , -01430);
begin
    execute immediate 'alter table ocd_param add(INDOCDFORMAPAGAMENTO NUMBER(1,0))';
    exception when column_exists then null;
end;
/

declare
    object_exists exception;
    pragma exception_init (object_exists , -00955);
begin
    execute immediate 'UPDATE ocd_param SET INDOCDFORMAPAGAMENTO=0';
    exception when object_exists then null;
end;
/