BPEL Process returns "empty variable/expression result."

Question

Hi,
I have an Asynchronous BPEL Process which uses a DB Adapter (which in turn uses a custom SQL Procedure) to insert a value in to a table and return a sequence value generated in the procedure back to the BPEL Process. The process inserts the value in to the table but the sequence is not returned back and i get the below error,
<selectionFailure xmlns="http://schemas.xmlsoap.org/ws/2003/03/business-process/">
<part name="summary">
<summary>
empty variable/expression result.
xpath variable/expression expression "/ns2:OutputParameters/ns2:X_NO" is empty at line 94, when attempting reading/copying it.
Please make sure the variable/expression result "/ns2:OutputParameters/ns2:X_NO" is not empty.
</summary>
</part>
</selectionFailure>
If i see the process flow the invoke activity shows the sequence value is returned from the procedure but when the invoke activity passes that value to the Assign activity its lost and the above error is displayed.
The details i see in Invoke activity is below,
<messages>
<Invoke_1_DBProcWrite_InputVariable>
<part xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" name="InputParameters">
<InputParameters
xmlns="http://xmlns.oracle.com/pcbpel/adapter/db/APPS/SUR_NEW_BPEL_PROC/">
<P_NAME>Vivek</P_NAME>
</InputParameters>
</part>
</Invoke_1_DBProcWrite_InputVariable>
<Invoke_1_DBProcWrite_OutputVariable>
<part xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" name="OutputParameters">
<db:OutputParameters xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:db="http://xmlns.oracle.com/pcbpel/adapter/db/APPS/SUR_NEW_BPEL_PROC/">
<X_NO>9</X_NO>
</db:OutputParameters>
</part>
<part xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
name="response-headers">[]</part>
</Invoke_1_DBProcWrite_OutputVariable>
</messages>
I use Jdeveloper version 10.1.3.3.0.4157. I did not recieve this error in Jdeveloper 10.1.3.1.
Please let me know how to resolve this issue.
Regards, Suresh

Answer 1

I have exactly the same problem!!!! I would appreciate someone from Product or other to explain why I can see the incoming variable being created but when XPath expression is attempted to extract a value so I can do an assignment I get a "empty variable/expression result".
Using JDEV10.1.3.3 and SOA 10.1.3.3 advanced install. My process is receiving a R12 Business Event listed here:
<?xml version="1.0" encoding="UTF-8" ?>
- <WF_EVENT_T xmlns="http://xmlns.oracle.com/xdb/APPS/BES_EVENT/BES_EVENT">
<PRIORITY xmlns="">50</PRIORITY>
<SEND_DATE xmlns="">2008-04-30T13:40:33.000-05:00</SEND_DATE>
<RECEIVE_DATE xmlns="">2008-04-30T13:40:40.000-05:00</RECEIVE_DATE>
<CORRELATION_ID xmlns="" />
- <PARAMETER_LIST xmlns="">
- <PARAMETER_LIST_ITEM>
<NAME>BO_ID</NAME>
<VALUE>123456</VALUE>
</PARAMETER_LIST_ITEM>
- <PARAMETER_LIST_ITEM>
<NAME>#CURRENT_PHASE</NAME>
<VALUE>201</VALUE>
</PARAMETER_LIST_ITEM>
</PARAMETER_LIST>
<EVENT_NAME xmlns="">oracle.apps.ar.hz.PersonBO.create</EVENT_NAME>
<EVENT_KEY xmlns="">777666</EVENT_KEY>
<EVENT_DATA xmlns="" />
- <FROM_AGENT xmlns="">
<NAME>WF_BPEL_QAGENT</NAME>
<SYSTEM>VIS12.US.ORACLE.COM</SYSTEM>
</FROM_AGENT>
<TO_AGENT xmlns="" />
<ERROR_SUBSCRIPTION xmlns="">TBo0FQQPy6ngQKjAuQAXWA==</ERROR_SUBSCRIPTION>
<ERROR_MESSAGE xmlns="" />
<ERROR_STACK xmlns="" />
</WF_EVENT_T>