Web Services Not Working because wwv_flow_collections view is empty

Question

Hello,
I followed this example to try and get a web service running in my Application:
http://apex.oracle.com/i/doc/advnc_rest_web_eg_2.htm
When I run the page and enter the zip code 43221 they recommend with a radius of 5, I get no results. When debugging and throwing the query into SQL Dev, I have no records in my wwv_flow_collections view. Looking at the tables that comprise the view, wwv_flow_collections$ and wwv_flow_collection_members$, these two tables would join on c.id = m.collection_id alone, but there are additional in-line selects involving the DUAL table that make the query return 0 records and therefore the view is empty. I've never messed with these views/tables, are these auto-populated by APEX? Can they be updated? Right now I cannot get any web services to work because of this. Here is the from clause for the wwv_flow_collections view:
FROM
wwv_flow_collections$ c,
wwv_flow_collection_members$ m
WHERE
c.session_id =
SELECT
v('SESSION')
FROM
dual
AND c.security_group_id =
SELECT
wwv_flow.get_sgid
FROM
dual
AND c.id = m.collection_id
AND c.flow_id =
SELECT
nv('FLOW_ID')
FROM
dual
Can anyone help? Thanks in advance!
John

Answer 1

John,
I have been working this week to set up the exact same thing and got the same empty result set that you have. In this case I believe it has nothing to do with APEX. I downloaded soapUI 4.0.1 which tests web services and used the WSDL described in the APEX Webservices tutorial for http://www.ignyte.com/webservices/ignyte.whatsshowing.webservice/moviefunctions.asmx?wsdl to create the same sample requests. It also returns no results.
So, I decided to use a different public WSDL and try to get it working. Here are my steps taken below:
BACKGROUND:
- I am using APEX 4.0 on an 11gR2 database, with ACLS set up for the APEX schema this app is using.
- First off, the site I used I just found through google. It is a currency conversion rate webservice. It is explained here: http://www.webservicex.net/CurrencyConvertor.asmx
- The WSDL is found here: http://www.webservicex.net/CurrencyConvertor.asmx?WSDL
SETTING UP THE WEBSERVICE:
1. In a new APEX application I went to "*Shared Components*" -> "*Web Service References*" -> "*Create*" to create a new web service reference
2. Selected manual
3. Called the webservice CURRENCY_TEST
4. Set the URL to http://www.webservicex.net/CurrencyConvertor.asmx
5. Set the Action to http://www.webserviceX.NET/ConversionRate (Action can be found in the WSDL - showing a few lines below)
<pre class="jive-pre">
<wsdl:binding name="CurrencyConvertorSoap" type="tns:CurrencyConvertorSoap">
<soap:binding transport="http://schemas.xmlsoap.org/soap/http"/>
<wsdl:operation name="ConversionRate">
<soap:operation soapAction="*http://www.webserviceX.NET/ConversionRate*" style="document"/>
<wsdl:input>
<soap:body use="literal"/>
</wsdl:input>
<wsdl:output>
<soap:body use="literal"/>
</wsdl:output>
</wsdl:operation>
</wsdl:binding>
</pre>
6. WSDL explains that the version is *1.1* in this case. (However, this same WSDL has the same operation for 1.2 so it probably would work)
7. No Authentication
8. soapUI 4.0.1 gave me the soap request which in this case is the following:
<pre class="jive-pre">
<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:web="http://www.webserviceX.NET/">
<soapenv:Header/>
<soapenv:Body>
<web:ConversionRate>
<web:FromCurrency>#FROM_CURRENCY#</web:FromCurrency>
<web:ToCurrency>#TO_CURRENCY#</web:ToCurrency>
</web:ConversionRate>
</soapenv:Body>
</soapenv:Envelope>
</pre>
9. Stored response in collection CURRENCY_COLLECTION
10. Saved my web service reference
11. Test the web service reference (you have to be on the web service references page and instead of the icon view of the report, use the list view. Click on the test icon to test the web service)
12. On the test page, change #FROM_CURRENCY# to USD (for US dollars) and #TO_CURRENCY# to EUR (Euros)
13. Click the test button and you should see a valid soap response with a currency rate within the ConversionRateResult tags
USING THE WEBSERVICE AND GETTING RESULTS:
1. Went back to the application and hit "*Create Page*" -> "*Form*" -> "*Form and Report on Web Service*"
2. Selected my CURRENCY_TEST web service reference
3. Next on the next page
4. For input parameters, left the defaults to create 2 inputs, From_Currency and To_Currency
5. Soap Style for this is Document (found in the WSDL as an attribute just after the soapAction attribute in the WSDL snippet above)
6. Message Format is Literal (Also found above in the wsdl:output for this operation under the use attribute)
7. XPATH is a bit complicated. In this case put */ConversionRateResponse* (I used the soapUI 4.0.1 to send the request and get back the soap response to see what the response tags would include and which path I'm going to)
8. Message Namespace is http://www.webserviceX.NET/ (which is also found in the response soap message - I'd really recommend a tool to test this outside of APEX)
9. For Parameter Names there is only one and it is ConversionRateResult (also found in the response soap message)
10. Finish and run the report.
OTHER GOTCHAS:
So I finally got this to work, but in my case I was querying a remedy webservice and the xml tags I get back are all xmlns:ns0 and all response tags prefaced with ns0:
In this case I had to after using the wizard go back and edit my query to change xmlns to xmlns:ns0 since the builder only assumes xmlns.
<pre class="jive-pre">
select extractValue(value(t),'/*/ns0:Assigned_Group','xmlns:ns0="urn:HPD_IncidentInterface_WS"') "Assigned_Group"
, extractValue(value(t),'/*/ns0:Assignee','xmlns:ns0="urn:HPD_IncidentInterface_WS"') "Assignee"
, extractValue(value(t),'/*/ns0:Resolution','xmlns:ns0="urn:HPD_IncidentInterface_WS"') "Resolution"
, extractValue(value(t),'/*/ns0:Status','xmlns:ns0="urn:HPD_IncidentInterface_WS"') "Status"
from wwv_flow_collections c,
table(xmlsequence(extract(c.xmltype001,'//ns0:HelpDesk_Query_ServiceResponse','xmlns:ns0="urn:HPD_IncidentInterface_WS"'))) t
where c.collection_name = 'INCIDENT_TEST'
</pre>
Good Luck!
Jonathon