Retrieve All records and display in Report using CAML query in Report Builder if Parameter value is blank

Question

Hello Experts,
i have created a report where i have one parameter field where user will pass parameter(e.g. EmpId). As per parameter record will fetched to report if no parameter is passed then it will display all records. I have done it by taking SqlServer Database as datasource.
by using Following method
Now i would like to do it by taking Sharepoint List as Datasource. For that what would be the CAML Query.
Here is my existing CAML query.
<RSSharePointList xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
  <ListName>Employees</ListName>
  <ViewFields>
    <FieldRef Name="Title" />
    <FieldRef Name="FirstName" />
    <FieldRef Name="LastName" />
    <FieldRef Name="FullName" />
    <FieldRef Name="UserName" />
    <FieldRef Name="Company" />
  </ViewFields>
  <Query>
    <Where>  
<Eq> 
    <FieldRef Name="Title" />
  <Value Type="Text">    
   <Parameter Name="EmployeeId"/>    
</Value>
</Eq>                  
    </Where>
  </Query>
</RSSharePointList>
The above code is working if i am passing an employeeId to Parameter. If nothing is passed, it is Not retrieving any record.
Please suggest
Thank you
saroj
saroj

Answer 1

Your problem follows the well-established pattern of using an "All" parameter filter in SSRS. There are a few approaches depending on the size of your data. The easiest one is to return all data from CAML and then filter it within SSRS, the following thread
provides some examples,
http://stackoverflow.com/questions/18203317/show-all-records-some-records-based-on-parameter-value.
Other options include passing all of the possible values within the CAML query when "All" is selected, using multiple Report Files to distinguish between both CAML queries, or to use multiple datasets with some logic to show/hide the correct one.
Dimitri Ayrapetov (MCSE: SharePoint)