Connect to Windows Desktop Search on Remote Machine

Question

I inherited a program which is using Windows Desktop Search (WDS) on a remote server to search indexed PDFss. The original coder did most of the code using VB 6 style programming, so when he accessed the Windows Desktop Search, he uses ADO Recordset objects.

Unfortunately, the code samples from Microsoft aren't working for me, as I keep getting an error saying "IErrorInfo.GetDescription failed with E_FAIL(0x80004005)."

Here is the code I am trying to use and the query I am sending:

Query:

SELECT "System.ItemPathDisplay" 
FROM "server"."SystemIndex" 
WHERE CONTAINS(*,'"widget*" AND "foo*"',1033) 
AND ("SCOPE" = 'file://server/networkshare') 
AND Contains(System.ItemType,'"txt"')  
ORDER BY System.ItemPathDisplay ASC 

Code:

// Thie uses SearchAPI interop assembly
CSearchManager manager = new CSearchManager();

// the SystemIndex catalog is the default catalog that windows uses
CSearchCatalogManager catalogManager = manager.GetCatalog("SystemIndex");

// get the ISearchQueryHelper which will help us to translate AQS --> SQL necessary to query the indexer
CSearchQueryHelper queryHelper = catalogManager.GetQueryHelper();

queryHelper.QueryWhereRestrictions = string.Format("AND (\"SCOPE\" = 'file://{0}/{1}')", "server", "networkshare");

// set the number of results we want
if (maxRows > 0)
{
   queryHelper.QueryMaxResults = maxRows;
}

// set the columns we want
queryHelper.QuerySelectColumns = "System.ItemPathDisplay";

if (sortCol != "System.ItemPathDisplay")
{
   // unless a sort column is specified in which case we will add that column too
   queryHelper.QuerySelectColumns = "System.ItemPathDisplay," + sortCol;
}

// if we have a file pattern 
if (filePattern.Length > 0)
{
   // then we add file pattern restriction, mapping cmd line style wildcards to SQL style wildcards
   string pattern = filePattern;
   pattern = pattern.Replace("*","%");
   pattern = pattern.Replace("?", "_");

   if (pattern.Contains("%") || pattern.Contains("_"))
   {
      queryHelper.QueryWhereRestrictions += " AND System.FileName LIKE '" + pattern + "' ";
   }
   else
   {
      // if there are no wildcards we can use a contains which is much faster as it uses the index
      queryHelper.QueryWhereRestrictions += " AND Contains(System.FileName, '" + pattern + "') ";
   }
}

// if we have file extensions
if (exts != null)
{
   // then we add a constraint against the System.ItemType column in the form of
   // Contains(System.ItemType, '.txt OR .doc OR .ppt') 
   queryHelper.QueryWhereRestrictions += " AND Contains(System.ItemType,'";
   bool fFirst = true;
   foreach (string ext in exts)
   {
      if (!fFirst)
      {
         queryHelper.QueryWhereRestrictions += " OR ";
      }
      queryHelper.QueryWhereRestrictions += "\""+ext+"\"";
      fFirst = false;
   }
   queryHelper.QueryWhereRestrictions += "') ";
}

// and we always have a sort column and direction, either the default or the one specified in the parameters
// so append an ORDER BY statement for it
queryHelper.QuerySorting = sortCol + " " + sortDirection;

// Generate SQL from our parameters, converting the userQuery from AQS->WHERE clause
string sqlQuery = queryHelper.GenerateSQLFromUserQuery(userQuery);

sqlQuery = sqlQuery.Replace("FROM \"SystemIndex\"", string.Format("FROM \"{0}\".\"SystemIndex\"", "server"));

// if they asked to show the sqlQuery
if (fShowQuery)
{
   // then output it to the console
   Console.WriteLine(sqlQuery);
}

// --- Perform the query ---
// create an OleDbConnection object which connects to the indexer provider with the windows application
System.Data.OleDb.OleDbConnection conn = new OleDbConnection(queryHelper.ConnectionString);

// open it
conn.Open();

// now create an OleDB command object with the query we built above and the connection we just opened.
OleDbCommand command = new OleDbCommand(sqlQuery, conn);

// execute the command, which returns the results as an OleDbDataReader.
OleDbDataReader WDSResults = command.ExecuteReader();

The error happens on the last line. Any help and/or thoughts would be greatly appreciated. Thanks for your time.

Wade

Answer 1

I wonder if it's your Query (wrong quotes in the wrong places). This is mine:

SELECT System.ItemName, System.ItemPathDisplay, System.ItemType, 
       System.Search.Rank 
FROM servername.SYSTEMINDEX 
WHERE SCOPE='file://servername/WebContent' 
AND System.ItemType <> 'Directory' 
AND ( 
   CONTAINS(System.Search.Contents,'*asdf*') 
   OR
   CONTAINS(System.FileName,'*asdf*')
)

Answer 2

I think your command is timing out! Try adding the line as follows:

// now create an OleDB command object with the query we built above and the connection we just opened.
OleDbCommand command = new OleDbCommand(sqlQuery, conn);
command.commandTimeout=0; <-- This will keep the connection open until it completes.

The default connection is only 30 seconds, so adding more time will allow the connection to remain open and complete the task. If the command timeout is exceeded then the balance of the lookup fails, hence why you get the error "GetDescription" failed.