SSRS Designer - XML Datasource - Parameter passing XML gets encoded, causes error on WS Request

Question

Hello,
I am attempting to query a List from SharePoint using the XML Datasource. I am forced to use this datasource as our infrastructure team will not be upgrading our SSRS 2008 farm to SSRS 2008 R2 anytime soon. 2008 R2 has Native SharePoint
List Datasources ( which works great FYI ). I already completed the report using the Native SP List DS, only to find out that my timing was not so great as 2008 R2 was not in production yet... /sigh, communication... anyways...
I have successfully queried the List using the XML Datasource. It is only when I try to use the CAML query in the query parameter that it fails. So, here is my Query:
<Query>
<SoapAction>http://schemas.microsoft.com/sharepoint/soap/GetListItems</SoapAction>
<Method Namespace="http://schemas.microsoft.com/sharepoint/soap/" Name="GetListItems">
<Parameters>
<Parameter Name="listName">
<DefaultValue>{DD3DE881-1F9D-4016-AD73-F7E1D9340880}</DefaultValue>
</Parameter>
<Parameter Name="query">
<DefaultValue>
<Query>
<Where>
<Gt>
<FieldRef Name="Modified" />
<Value Type="DateTime">2011-03-01</Value>
</Gt>
</Where>
</Query>
</DefaultValue>
</Parameter>
</Parameters>
</Method>
<ElementPath IgnoreNamespaces="True">*</ElementPath>
</Query>
I will be replacing that hard date with something like =DateAdd("d",-7,Now()) later, but focusing on the task at hand...
Here is the error ( trimmed so you don't need to read the whole stack ):
<soap:Body>
<soap:Fault>
<faultcode>soap:Server</faultcode>
<faultstring>Exception of type 'Microsoft.SharePoint.SoapServer.SoapServerException' was thrown.</faultstring>
<detail>
<errorstring xmlns="http://schemas.microsoft.com/sharepoint/soap/">Element &lt;Query&gt; of parameter query is missing or invalid.</errorstring>
<errorcode xmlns="http://schemas.microsoft.com/sharepoint/soap/">0x82000000</errorcode>
</detail>
</soap:Fault>
</soap:Body>
The key to that error is:  Element &lt;Query&gt; of parameter query is missing or invalid.
So I see that it is being encoded, so I decided to capture the actual Webservice request with Fiddler:
<?xml version="1.0" encoding="utf-8"?>
<soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/">
<soap:Body>
<GetListItems xmlns="http://schemas.microsoft.com/sharepoint/soap/">
<query>
&lt;Query&gt;
&lt;Where&gt;
&lt;Gt&gt;
&lt;FieldRef Name="Modified" /&gt;
&lt;Value Type="DateTime"&gt;2011-03-01&lt;/Value&gt;
&lt;/Gt&gt;
&lt;/Where&gt;
&lt;/Query&gt;
</query>
<listName>{DD3DE881-1F9D-4016-AD73-F7E1D9340880}</listName>
</GetListItems>
</soap:Body>
</soap:Envelope>
So now that we know that somehow the XML parameter of "query" is being encoded. How do I tell the SSRS designer that for this XML datasource's dataset query, I do not wish to encode that parameter?  I have searched all day today and came up with
very little. I found a few posts with a simliar question, but no solution was ever mentioned.
The closest to a likely solution was this Post :
http://social.msdn.microsoft.com/Forums/en-US/sqlreportingservices/thread/8a9ba2fc-26cd-423e-bbbf-a16b5c9722f5/
in particular this phrase interested me:
"Query parameters of type Msxml2.DOMDocument30 are passed as XML. Parameters of type String which happen to contain XML are passed as strings and are XML encoded in the SOAP message. The function CXml(String) converts a string
into an Msxml2.DOMDocument30 and can be used in query parameter expressions."
Similar to the poster of that question, I also cannot find a way to define the parameter as an XML type or the use of this mysterious CXML() function in the expression builder...
I'm looking for a Microsoft resource to tell me whats going on here, but if anyone else has a workaround or an idea, I would be happy to try it out.
Regards,
-Ryan, Solution Architect

Answer 1

Hi Ryan,
Thanks for your question, from your statement, it seems that you want to give a default value for the parameter named query, right? If so I would recommend you achieve this requirement in report level, please follow these:
1. Create a parameter named Date, select Date/Time as data type.
2. Move to Default values tab, then click Add button ->type in  =DateAdd("d",-7,Now())  as defult value's expression.
3. Right-cilck the dataset, and then select DataSet properties.
4. Move to Filters tab, click add button to add a filter.
5. In the drop-down list of Expression, select Modified datefield with Date/Time datatype.
6. Type in =Parameters!Date.Value in value's textbox.
Similar thread, please get a reference from this
http://social.technet.microsoft.com/Forums/en-US/sqlreportingservices/thread/24d30b00-139e-4487-9fb1-02f460b432f9
If you have any question, please feel free to ask.
Thanks,
Challen Fu 
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