Need to know the column names in my dynamic select clause

Question

Dear All,
Please go through the following code. While executing the following code i am getting an error saying that dbms_sql.describe_columns overflow, col_name_len=35. Use describe_columns2.
Please guide me how to proceed further. Or please help me, how can i get the column names when i issue a dynamic select clause.
DECLARE
CUR INTEGER;
COL_CNT INTEGER ;
A INTEGER;
SEL_CLAUSE VARCHAR2(2000);
DESC_T DBMS_SQL.DESC_TAB;
REC DBMS_SQL.DESC_REC;
b number;
BEGIN
SEL_CLAUSE := 'SELECT 1,2,DECODE(1,1,''ONE'',2,''TWO'',3,''THREE'') FROM DUAL';
--'SELECT ROWID,PARA_SUB_CODE,DECODE('||''''||'ENG'||''''||','||''''||'ENG'||''''||',PARA_NAME,PARA_BL_NAME),NULL,NULL FROM PCOM_APP_PARAMETER';
--'SELECT 1,2,DECODE(1,1,''ONE'',2,''TWO'') FROM DUAL';
DBMS_OUTPUT.PUT_LINE( SEL_CLAUSE );
CUR := DBMS_SQL.OPEN_CURSOR;
DBMS_SQL.PARSE(CUR,SEL_CLAUSE,DBMS_SQL.NATIVE);
DBMS_SQL.DESCRIBE_COLUMNS(CUR,COL_CNT,DESC_T);
B := desc_t.first;
FOR J IN 1..COL_CNT
LOOP
DBMS_OUTPUT.PUT_LINE('J := '||J || ' COL CNT ' || COL_CNT);
END LOOP;
BEGIN
A := DBMS_SQL.EXECUTE(CUR);
EXCEPTION
WHEN OTHERS THEN
NULL;
END;
END;
Regards,
Balaji

Answer 1

Is there any way can i have it directly??It does not work with static SQL either. Dynamic SQL is no different.
SQL> select 1 x from dual where x = 1 ;
select 1 x from dual where x = 1
ERROR at line 1:
ORA-00904: "X": invalid identifier
SQL>As suggested already, you will need to use alias if you want your select expression to be referred in the where clause.
SQL> BEGIN
  2      FOR rec IN (SELECT *
  3                  FROM   (SELECT 1,
  4                                 2,
  5                                 DECODE(1, 1, 'ONE', 2, 'TWO', 3, 'THREE') "DECODE(1, 1, 'ONE', 2, 'TWO', "
  6                          FROM   DUAL)
  7                  WHERE  "DECODE(1, 1, 'ONE', 2, 'TWO', " = 'ONE')
  8      LOOP
  9          NULL;
10      END LOOP;
11  END;
12  /
PL/SQL procedure successfully completed.
SQL>Message was edited by:
Kamal Kishore