请教一个sql语句

SQL> CREATE OR REPLACE FUNCTION get_col (tab VARCHAR2)
  2     RETURN VARCHAR2
  3  IS
  4     col_c2   VARCHAR2 (4000);
  5     sqlstr   VARCHAR2 (4000);
  6  BEGIN
  7     sqlstr := ' select ';
  8  
  9     FOR cur IN (SELECT column_name
 10                   FROM user_col_comments
 11                  WHERE table_name = UPPER (tab))
 12     LOOP
 13        col_c2 := col_c2 || cur.column_name || ',';
 14     END LOOP;
 15  
 16     col_c2 := RTRIM (col_c2, 1);
 17     col_c2 := SUBSTR (col_c2, 1, LENGTH (col_c2) - 1);
 18     sqlstr := sqlstr || col_c2 || ' from ' || tab;
 19     EXECUTE IMMEDIATE sqlstr;
 20  
 21     RETURN sqlstr;
 22  END;
 23  /Function created.SQL> select get_col('a') from dual
  2  /GET_COL('A')
-----------------------------------------------------------------
 select RECEIVE_MONTH,DEFECT,DEFECT_TIMES,TYPE from aSQL> 
SQL> select get_col('ABMFV_ACT_DRIVER_SOURCES_V') from dual
  2  /GET_COL('ABMFV_ACT_DRIVER_SOURCES_V')
----------------------------------------------------------------------------------------------------
 select DATA_SET_NAME,SOURCE,SOURCE_ACTIVITY,SOURCE_ACTIVITY_NAME,SOURCE_ACTIVITY_DEPT,SOURCE_ACTIVI
TY_DEPT_NAME,SOURCE_BEGIN_DATE,SOURCE_BEGIN_EFFECTIVE_DATE,SOURCE_END_DATE,SOURCE_ID,SOURCE_NAME,SOU
RCE_DEPT,SOURCE_DEPT_NAME,SOURCE_DEPT_ACTIVITY,SOURCE_DEPT_ACTIVITY_ID,SOURCE_DEPT_ACTIVITY_NAME,SOU
RCE_DEPT_ACTIVITY_TYPE_CODE,SOURCE_DEPT_ID,SOURCE_TYPE,SOURCE_TYPE_CODE,SOURCE_VALUE,ACTIVITY_DRIVER
,ACTIVITY_DRIVER_ID,ACTIVITY_DRIVER_NAME,ACTIVITY_DRIVER_DEPT,ACTIVITY_DRIVER_DEPT_NAME,ACTIVITY_DRI
VER_DEPT_ID,ACTIVITY_DRIVER_TYPE_CODE,MASTER_LIST,MASTER_LIST_ID,MASTER_LIST_NAME,MODEL,MODEL_ID,MOD
EL_NAME,DATA_SET,DATA_SET_ID from ABMFV_ACT_DRIVER_SOURCES_V
SQL> 这样子得到除了不要的其他字段可以吗？