（1）select mark, wm_concat(status) from DISSENT_INFO t GROUP BY mark;
查出来的数据
mark status
222 1007,1006
333 1008,1008
444 1008
（2）
SQL> select deptno,listagg(ename,',')within group(order by sal)name from emp group by deptno;
DEPTNO NAME
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10 MILLER,CLARK,KING
20 SMITH,ADAMS,JONES,FORD,SCOTT
30 JAMES,MARTIN,WARD,TURNER,ALLEN,BLAKE