Query personal gdb using ORDER BY and DISTINCT clause

QueryGDBTables

public ICursor QueryRowViaQueryDef(IFeatureWorkspace featureWorkspace, String tables, String subFields, String whereClause)
        {
            // Create the query definition.
            IQueryDef2 queryDef = featureWorkspace.CreateQueryDef() as IQueryDef2;

            // Provide a list of table(s) to join.
            queryDef.Tables = tables;
            
            // Declare the subfields to retrieve.
            queryDef.SubFields = subFields;

            // Assign a where clause to filter the results.
            queryDef.WhereClause = whereClause;
            queryDef.PrefixClause = "DISTINCT";
            queryDef.PostfixClause = "ORDER BY "+subFields+" ASC";
            // Evaluate queryDef to execute a database query and return a cursor to the application.
            ICursor cursor = queryDef.Evaluate();
            return cursor;
        }