oracle sql listagg [重复]

SELECT deptno, 
       LISTAGG(ename, ',') WITHIN GROUP (ORDER BY ename) AS employees
  FROM emp
 GROUP BY deptno;

错误：- ORA-00923：在预期位置未找到 FROM 关键字 00923. 00000 - “在预期位置未找到 FROM 关键字” *原因：
*操作：错误位于行：1 列：42

Oracle Database 11g 企业版版本 11.1.0.7.0 - 64 位生产版

For the 10gR2 or 11gR1Oracle 版本中，您可以使用分层查询，其贡献为sys_connect_by_path :

with emp( ename, deptno ) as
(
 select 'CLARK',10 from dual union all 
 select 'MILLER',10 from dual union all
 select 'KING',10 from dual union all
 select 'FORD',20 from dual union all
 select 'SCOTT',20 from dual union all
 select 'JONES',20 from dual union all
 select 'SMITH',20 from dual union all
 select 'ADAMS',20 from dual union all
 select 'WARD',30 from dual union all
 select 'MARTIN',30 from dual union all
 select 'TURNER',30 from dual union all
 select 'JAMES',30 from dual union all
 select 'ALLEN',30 from dual union all
 select 'BLAKE',30 from dual
)
select deptno, ltrim(sys_connect_by_path(ename, ','), ',') as enames
  from (select deptno,
               ename,
               row_number() over(partition by deptno order by ename) as rn
          from emp)
 where connect_by_isleaf = 1
connect by deptno = prior deptno
       and rn = prior rn + 1
 start with rn = 1;

DEPTNO  ENAMES
------  ------------------------------------
  10    CLARK,KING,MILLER
  20    ADAMS,FORD,JONES,SCOTT,SMITH
  30    ALLEN,BLAKE,JAMES,MARTIN,TURNER,WARD