declare 
  column_exists exception;
  pragma exception_init (column_exists , -01430);
begin 
  execute immediate 'ALTER TABLE RECARGA_CELULAR ADD (TIPO_RECARGA NUMBER(2,0))';
  exception when column_exists then null;
end;
/
declare
    object_exists exception;
    pragma exception_init (object_exists , -00955);
begin
    execute immediate 'update RECARGA_CELULAR set TIPO_RECARGA = 0 where activo = 1';
    exception when object_exists then null;
end;
/
declare 
  column_exists exception;
  pragma exception_init (column_exists , -01430);
begin 
  execute immediate 'ALTER TABLE RECARGA_CELULAR ADD (AFFILIATION_KEY VARCHAR(20),SIGNER_CODE VARCHAR(20), SERIAL_NUMBER VARCHAR(20))';
  exception when column_exists then null;
end;
/
declare
    object_exists exception;
    except_00957  exception;
 
    pragma exception_init (object_exists , -01430);
    pragma exception_init (except_00957 , -00957);
begin
   execute immediate 'ALTER TABLE RECARGA_CELULAR MODIFY (CELL_PHONE_NUMBER NULL)';
   exception 
       when object_exists then null;
       when except_00957 then null;
end;
/
declare
    object_exists exception;
    except_00957  exception;
 
    pragma exception_init (object_exists , -01430);
    pragma exception_init (except_00957 , -00957);
begin
   execute immediate 'ALTER TABLE RECARGA_CELULAR MODIFY (NSU NULL)';
   exception 
       when object_exists then null;
       when except_00957 then null;
end;
/
declare
    object_exists exception;
    except_00957  exception;
 
    pragma exception_init (object_exists , -01430);
    pragma exception_init (except_00957 , -00957);
begin
   execute immediate 'ALTER TABLE RECARGA_CELULAR MODIFY (AUTHORIZATION_CODE NULL)';
   exception 
       when object_exists then null;
       when except_00957 then null;
end;
/
declare
    object_exists exception;
    except_00957  exception;
 
    pragma exception_init (object_exists , -01430);
    pragma exception_init (except_00957 , -00957);
begin
   execute immediate 'ALTER TABLE RECARGA_CELULAR MODIFY (FACE_AMOUNT NULL)';
   exception 
       when object_exists then null;
       when except_00957 then null;
end;
/