[oracle]sys_connect_by_path用法（一个select语句中多条数据拼成一条数据）

create table demoTable(
id number ,
content varchar2(30)
);

insert into demotable (ID, CONTENT)
values (1, 'content1');

insert into demotable (ID, CONTENT)
values (1, 'content2');

insert into demotable (ID, CONTENT)
values (2, 'content3');

insert into demotable (ID, CONTENT)
values (3, 'content4');

select max(sys_connect_by_path(content,' ')) from (
select id,content ,rownum rn from demoTable
)
start with rn=1
connect by prior rn=rn-1;