How do I buid a WCF Query on the fly?

I'd like to build some linq or alternatively, build a query string on the fly and pass it to a WCF Data Service (with Entity Framework data model).

Something like this:

 public List<DocumentInformationRecord> SearchClientDocs(string clientCode,
            strin开发者_开发百科g clientName, string contactName, string groupCode, string groupName,
            string filename, string createdby, DateTime dateFrom, DateTime dateTo)
 {
   List<DocumentInformationRecord> results = new List<DocumentInformationRecord>();
   if(!string.IsNullOrEmpty(clientCode)) 
   //Add the client code clause...

etc..

var qry = from c in context.DocumentInformationRecord.where(dynamicQuery);

            //Etc......

Any ideas? I tried the predicate builder (http://www.albahari.com/nutshell/predicatebuilder.aspx) but got some invalid operation exceptions.....

I am not sure I entirely understand your question, but I have sometimes written code to build up LINQ queries with different parts depending on input. Typically that goes something like this:

var qry = from item in someList
          select item;

if (nameFilter != null)
{
    qry = qry.Where(item => item.Name == nameFilter);
}

if (someOtherFilter != null)
{
    qry = qry.Where(item => item.SomeOtherStuff == someOtherFilter);
}
// and so on

That way you can build the query step by step. You can do this because of deferred execution; the query will not be executed against the data source until you start iterating over the result.

Not sure if it will suit your situation, but you can use expression trees to build dynamic queries. There is a good tutorial here