C# - How To Properly Populate DataSet Twice

I've got a SqlConnection with a sqlquery that may not bring any results. On the rare occasion this happens, I have another sqlquery and another connection to the database. There has to be a better way to do this, no?

On a side note, is this best to close the connection after .Fill? I assume so, but haven't seen it used anywhere.

SqlConnection dbSqlConnection = new SqlConnection(--);
SqlDataAdapter dbSqlDataAdapter = new SqlDataAdapter(sqlquery, dbSqlConnection);
DataSet dbDataSet = new DataSet();
dbSqlDataAdapter.Fill(dbDataSet, "popGrid");
dbSqlConnection.Close();
if (dbDataSet.Tables["popGrid"].Rows.Count == 0)
{
SqlDataAdapter newSqlDataAdapter = new SqlDataAdapter(sqlquery2, dbSqlConnection);
newSqlDataAdapter.Fill(dbDataSet, "popGrid");
dbSqlConnection.Close();