SQL & PL/SQL

I am on 11g2. Trying to generate JSON strings for various queries. However, I could not generate the targeted string structure, which looks like this:

[{
  "key": {
  "_id": "keyVal1"
  },
  "values": {
  "col1": "val1",
  "col4": "val2"
  }
}, {
  "key": {
  "_id": "keyVal2"
  },
  "values": {
  "col1": "val1",
  "col4": "val2"
  }
}]

So it is basically, a list of objects (say, outer objects), where each outer object, contains two inner objects inside (key & values). My goal is convert each row of my query into an outer object with objects inside.

I do not want to hardcode the structure, as it will be used with many queries. I am trying to find a flexible way to do it. My best source so far was http://ora-00001.blogspot.my/2010/02/ref-cursor-to-json.html

I thought the last example using cursor expression would help me:

declare
l_json clob;
begin
l_json := json_util_pkg.sql_to_json ('select d.deptno, d.dname,
cursor (select e.*
from emp e
where e.deptno = d.deptno) as the_emps
from dept d');
dbms_output.put_line (substr(l_json, 1, 10000));
end;

But unfortunately, it was not what I am looking for. Using cursor expression generates a list of objects, and inside each object there is another list. I want to generate two objects inside each object.

I tried to play with the query, in futile.

Is there any dynamic way I can generate the structure above?

UPDATE:

Here is example of what I am trying to achieve. Suppose the table is:

createtableemp(
  empno    number(4,0),
  ename    varchar2(10),
  job      varchar2(9),
  mgr      number(4,0),
  hiredate date,
  sal      number(7,2),
  comm     number(7,2),
  deptno   number(2,0)
);
insert into emp
values(
 7839, 'KING', 'PRESIDENT', null,
 to_date('17-11-1981','dd-mm-yyyy'),
 5000, null, 10
);
insert into emp
values(
 7698, 'BLAKE', 'MANAGER', 7839,
 to_date('1-5-1981','dd-mm-yyyy'),
 2850, null, 30
);
insert into emp
values(
 7782, 'CLARK', 'MANAGER', 7839,
 to_date('9-6-1981','dd-mm-yyyy'),
 2450, null, 10
);
insert into emp
values(
 7566, 'JONES', 'MANAGER', 7839,
 to_date('2-4-1981','dd-mm-yyyy'),
 2975, null, 20
);
insert into emp
values(
 7788, 'SCOTT', 'ANALYST', 7566,
 to_date('13-JUL-87','dd-mm-rr') - 85,
 3000, null, 20
);
insert into emp
values(
 7902, 'FORD', 'ANALYST', 7566,
 to_date('3-12-1981','dd-mm-yyyy'),
 3000, null, 20
);
insert into emp
values(
 7369, 'SMITH', 'CLERK', 7902,