Accessing a sequence which does not exists

Question

i have pl/sql code as below and the sequence  value is displayed based on condition.In case the sequence  does not exists and condition fails  the pl/sql is not getting compiled and throws error  saying that  sequence does not exists.
For eg:
declare
i number;
begin
if ( 1=2)  then
select  top_seq.nextval into i from dual;
dbms_output.put_line('i'||i);
end if;
end;
in above sequence  does not exist and condition is failed as it never access sequence, does the pl/sql  code execute successfully and  which is not  happening as it throws error  . sequence does not exists.

Answer 1

910111 wrote:
Hi,
as Frank mentioned before, you can achieve that by using dynamic sql, see following example:
DECLARE
  lc_sql       VARCHAR2(4000);
  ln_seqExists NUMBER       := 0;
  lc_seqName   VARCHAR2(30) := 'TOP_SEQ';
  i            NUMBER;
BEGIN
  SELECT NVL(COUNT(*),0)
  INTO ln_seqExists
  FROM user_sequences
  WHERE sequence_name = lc_seqName;
  IF ln_seqExists     = 0 THEN
    lc_sql           := 'CREATE SEQUENCE ' || lc_seqName;
    EXECUTE immediate lc_sql;
  END IF;
  IF ( 1    = 1) THEN
    lc_sql := 'select  top_seq.nextval from dual';
    EXECUTE immediate lc_sql INTO i;
    dbms_output.put_line('i: ' || i);
  END IF;
EXCEPTION
WHEN OTHERS THEN
  dbms_output.put_line(sqlerrm);
END;
Regards
Not everything that can be done should be done .... 
Before showing someone how to shoot themselves in the foot, it would be best to determine that shooting themselves in the foot is the best and most appropriate course of action.