Change your code to:
DataSet ds = databaseServer.ConnectionContext.ExecuteWithResults("Select DataValue from TABLE where KEYField = 'DealershipName'");
The "USE DATABASE;", first, you may not need it. Second it, if you mean "USE MyDatabaseName;" , try it with a semi colon after the name.
More important to your question : then do a
Console.Writeline (ds.GetXml );
You'll then "see" the DataSet, the DataTable, the row inside the DataTable from which to "pluck" your scalar value.
string value = string.Empty;
if(null!=ds) {
if(null!=ds.Tables) {
if(ds.Tables.Count > 0) {
if(null!=ds.Tables[0].Rows) {
if(ds.Tables[0].Rows.Count > 0) {
if(null!=ds.Tables[0].Rows[0].Columns){
if(ds.Tables[0].Rows[0].Columns.Count > 0)
{
value = ds.Tables[0].Rows[0].Columns[0].Value;
}}}}}}}
"Count" may be "Length", I'm going from memory.
My code is untested from memory, so take it with a grain of salt.