PLSQL and XMLTYPE -- Trying to pass cursor record into a XMLTYPE query.

Question

Hi all --
I'm trying to pass records from a cursor into a xmltype query, with no success. If i hard code what the cursor record is, it works just fine, but when I use cursor_rec.value, I think it is taking that strin literally. Here is a simple example of what i'm trying to do.
Brief Background -- I have two tables (OPLAN, OPLAN_SUB_CONT) with an XMLTYPE column. OPLAN contains the bulk/main XML with about 30 elemets, while OPLAN_SUB_CONT contains the xml files which either inserts or updates any of the 30 elements. Instead of hard coding 30 statments to check each element, I created a cursor to cycle through the possible elements. If an element exists i do something , if not i go the next element.
This returns null, using elements_rec.element_name in the query...
declare
cursor cur_get_elements is
select element_name
from oplan_element_attribs
where parent_element='Transactions'
and element_name='OPLAN_STATUS';
elements_rec cur_get_elements%rowtype;
v_element number;
begin
for elements_rec in cur_get_elements
Loop
dbms_output.put_line ('before extract');
select nvl(count(value(p)),0)
into v_element
from oplan_sub_content_xml oscx,
table(xmlsequence(extract(SUBSCRIPTION_CONTENT,'Transactions/elements_rec.element_name'))) p;
if v_element =0
then dbms_output.put_line ('Element ' || elements_rec.element_name || ' is null');
elsif v_element > 0
then dbms_output.put_line ('Element ' || elements_rec.element_name || ' is not null');
end if;
end loop;
end;
SQL> /
before extract
Element OPLAN_STATUS is null
PL/SQL procedure successfully completed.
If i hard code the element_name (elements_rec.element_name) on line 16 (line wraps) to "OPLAN_STATUS' i get desired results ... returns not null
declare
cursor cur_get_elements is
select element_name
from oplan_element_attribs
where parent_element='Transactions'
and element_name='OPLAN_STATUS';
elements_rec cur_get_elements%rowtype;
v_element number;
begin
for elements_rec in cur_get_elements
Loop
dbms_output.put_line ('before extract');
select nvl(count(value(p)),0)
into v_element
from oplan_sub_content_xml oscx,
table(xmlsequence(extract(SUBSCRIPTION_CONTENT,'Transactions/OPLAN_STATUS'))) p;
if v_element =0
then dbms_output.put_line ('Element ' || elements_rec.element_name || ' is null');
elsif v_element > 0
then dbms_output.put_line ('Element ' || elements_rec.element_name || ' is not null');
end if;
end loop;
end;
SQL> /
before extract
Element OPLAN_STATUS is not null
PL/SQL procedure successfully completed.
Any ideas?
Thanks!

Answer 1

I should try everything before posting! Sorry, got it to work...
replaced ..
select nvl(count(value(p)),0)
into v_element
from oplan_sub_content_xml oscx,
table(xmlsequence(extract(SUBSCRIPTION_CONTENT,'Transactions/elements_rec.element_name'))) p;
with
select nvl(count(value(p)),0)
into v_element
from oplan_sub_content_xml oscx,
table(xmlsequence(extract(SUBSCRIPTION_CONTENT,'Transactions/' || elements_rec.element_name || ''))) p;