Need to concat nodes

Question

SQL> declare
2 x1 xmltype := xmltype ('<a>1</a>');
3 x3 xmltype;
4 begin
5 select xmlconcat (x1, xmlconcat(xmlsequence(cursor(select * from T_suspect_makers where case
_id=5))))
6 into x3
7 from dual;
8
9 dbms_output.put_line (x3.getstringval ());
10 end;
11 /
declare
ERROR at line 1:
ORA-00932: inconsistent datatypes: expected - got -
ORA-06512: at line 5
why this error is coming?
what I need to actually is:
I need to have a output like:
<table_name>table1</table_name>
<ROW>
<CASE_ID>5</CASE_ID>
<PROS_SEQ>183934</PROS_SEQ>
<SM_CODE>S</SM_CODE>
</ROW>

Answer 1

what I need actually is: I need to have a output like:Something like this?:
SQL>  declare
x1   xmltype := xmltype('<table_name>table1</table_name>');
x3   xmltype;
begin
select xmlforest(xmlconcat(x1, 
                            xmltype(cursor(select empno, ename, job, sal from emp where empno=7788)).extract('ROWSET/*'))"table")
  into x3
  from dual;
  dbms_output.put_line (x3.getstringval ());
end;
<table><table_name>table1</table_name>
<ROW><EMPNO>7788</EMPNO><ENAME>SCOTT</ENAME><JOB>ANALYST</JOB><SAL>3000</SAL></ROW></table>