sql - oracle sql列表

Question

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

错误：- ORA-00923：在预期的位置找不到 FROM 关键字 00923。00000 -“在预期的位置找不到 FROM 关键字” *原因：
*操作：行错误：1 列：42

Oracle Database 11g 企业版 11.1.0.7.0 - 64 位生产

Answer 1

对于 Oracle 的10gR2or11gR1版本，您可以使用具有以下贡献的分层查询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