How to set variable equal to empty XML node in SQL Developer - sql

Question

I am getting a 'method dispatch on NULL SELF argument is disallowed' error when running the below code. I manually went through my XML file and found that 'OtherLocation' is sometimes blank. I commented out the line associated with that node and that fixed the error. I am working with a large XML file that holds event information. Some events supplied information whereas other's did not.
I need to include the information if it is there and set the variable to ' ' if not.
How do I go about that?
WHILE l_xml.existsNode('/ResultOfEvent/Items/Event[' || v_count || ']') = 1 LOOP
l_eventid := l_xml.extract('/ResultOfEvent/Items/Event[' || v_count || ']/EventId/text()').getStringVal();
l_eventname := l_xml.extract('/ResultOfEvent/Items/Event[' || v_count || ']/EventName/text()').getStringVal();
l_organizationid := l_xml.extract('/ResultOfEvent/Items/Event[' || v_count || ']/OrganizationId/text()').getStringVal();
l_organizationname := l_xml.extract('/ResultOfEvent/Items/Event[' || v_count || ']/OrganizationName/text()').getStringVal();
l_description := l_xml.extract('/ResultOfEvent/Items/Event[' || v_count || ']/Description/text()').getStringVal();
--l_otherlocation := l_xml.extract('/ResultOfEvent/Items/Eventt[' || v_count || ']/OtherLocation/text()').getStringVal();
insert into xml_test values(l_eventid, l_eventname, l_organizationid, l_organizationname, l_otherlocation, l_description);
v_count := v_count + 1;
END LOOP;
EDIT
Upon doing more research on xml.extract I found that it will return a null xmltype if the xml element is empty. Is there a way to do a check for null before attempting to add? If the element is empty then, I need to insert ' ' into the corresponding table.

Answer 1

Ok after some time, I was finally able to come up with a working solution. The altered code below produces no error.
WHILE l_xml.existsNode('//ResultOfEvent/Items/Event[' || v_count || ']') = 1 LOOP
l_eventid := l_xml.extract('//ResultOfEvent/Items/Event[' || v_count || ']/EventId/text()').getStringVal();
l_eventname := l_xml.extract('//ResultOfEvent/Items/Event[' || v_count || ']/EventName/text()').getStringVal();
l_organizationid := l_xml.extract('//ResultOfEvent/Items/Event[' || v_count || ']/OrganizationId/text()').getStringVal();
l_organizationname := l_xml.extract('//ResultOfEvent/Items/Event[' || v_count || ']/OrganizationName/text()').getStringVal();
v_otherlocation := l_xml.extract('//ResultOfEvent/Items/Event[' || v_count || ']/OtherLocation/text()');
if v_otherlocation IS NULL then
l_otherlocation := ' ';
else
l_otherlocation := v_otherlocation.getStringVal();
end if;
l_description := l_xml.extract('//ResultOfEvent/Items/Event[' || v_count || ']/Description/text()').getStringVal();
insert into XMLPROCESSEDTABLE values(l_eventid, l_eventname, l_organizationid, l_organizationname, l_otherlocation, l_description);
v_count := v_count + 1;
END LOOP;
Creating a new variable v_otherlocation that is equal to the xmltype is what fixed the problem. The error I was getting was because of the getStringVal(). If l_xml.extract returned null then getStringVal() was trying to pull a value out of a null object.