Search from code using FullTextSqlQuery - Search Service unavailable

Question

I'm trying to search a Sharepoint 2007 site using the FullTextSqlQuery class, but I keep getting the following error "The search request was unable to connect to the Search Service"

My code looks like this

                create a new FullTextSqlQuery class - use property intializers to set query               
                scope = "BuySale";
                FullTextSqlQuery myQuery = new FullTextSqlQuery(SPContext.Current.Site)
                {
                    QueryText = "SELECT Path FROM SCOPE() WHERE  \"SCOPE\" = '" + scope + "'",
                    ResultTypes = ResultType.RelevantResults

                };
                ResultTableCollection queryResults = myQuery.Execute();
                ResultTable queryResultsTable = queryResults[ResultType.RelevantResults];                   
                queryDataTable.Load(queryResultsTable, LoadOption.OverwriteChanges);

Error from ULS log is this

Danish version

Log Query: Søgeanmodningen kunne ikke oprette forbindelse til søgetjenesten. Yderligere oplysninger: Object or data matching the name, range, or selection criteria was not found within the scope of this operation.

English version

Log Query: The search request was unable to connect to the Search Service. Yderligere oplysninger: Object or data matching the name, range, or selection criteria was not found within the scope of this operation.

I've checked that all services is running and the scope exits. I'm able to use the scope using sharepoint normal search and using the "SearchCoder" app that can help create search query.

Any ideas would be greatly appreciated.

Answer 1

Found the soltuion after spending a few more hours on google.

I was using the wrong dll to resolve the FullTextSqlQuery class

I was using this Microsoft.SharePoint.Search.Query // WSS

but should have been using this using Microsoft.Office.Server.Search.Query // MOSS

Thanks to Chris O'Connor

http://sharepointroot.com/2009/11/14/fulltextsqlquery-throwing-exception-this-site-is-not-assigned-to-an-indexer