Missing expression Error using pivot function

Question

Hi,
When i am running the query:
The query needs to display name and total:
{select  *}
{  from  (select name,nvl(sal,0) tot from tablea }
{                          GROUP BY name,nvl(sal,0) }
{  pivot(SUM(tot) for name in (select ltrim(sys_connect_by_path(''''||name||'''', ','), ',') str}
{from ( select row_number() over(order by name) rn}
{       ,      name}
{       from  tablea}
{where connect_by_isleaf=1}
{start with rn=1}
{connect by rn=prior rn+1);}
When running the above query its giving error:
ORA-00936: missing expression at line select ltrim(sys_connect_by_path
Any help will be needful for me

Answer 1

If you use pivot, you have to hardcode all your values in the FOR IN clause.
SQL> select *
  2   from (select ename,nvl(sal,0) tot from emp
  3   GROUP BY ename,nvl(sal,0)
  4   )
  5   pivot(SUM(tot) for ename in ( 'SCOTT' ,'KING') )
  6  ;
   'SCOTT'     'KING'
      3000       5000You can't substitute the literal list of values (in my example ('SCOTT','KING') with a subquery producing similar result.
Only with pivot xml you can put there a subquery, in that case, the result however doesn't have to be in form of comma separated values (like you try to achieve with sys_connect_by_path)
SQL> select *
  2   from (select ename,nvl(sal,0) tot from emp
  3   GROUP BY ename,nvl(sal,0)
  4   )
  5   pivot xml (SUM(tot) for ename in ( select ename from emp where ename like 'S%' ) )
  6  ;
ENAME_XML
<PivotSet><item><column name = "ENAME">SCOTT</column><column name = "SUM(TOT)">3000</column></item><
item><column name = "ENAME">SMITH</column><column name = "SUM(TOT)">800</column></item></PivotSet>Best regards
Maxim