我尝试使用merge语句在Informix v10.0中进行插入/更新，但是会引发语法错误：

create table source(id int, account int, age int);
create table target (id int, account int, age int);

insert into source values(1, 1200, 25);
insert into source values(2, 1300, 28);
insert into source values(3, 1400, 45);

merge into target t 
using source s on t.id = s.id
when matched then
update
set t.id = s.id, t.account = s.account, t.age = s.age
when not matched then
insert (t.id, t.account, t.age)
values (s.id, s.account, s.age);

select * from target;

能否请你帮忙？