// meanwhile: show the user that you are busy:
this.ShowBusy(true); // show picture box?

// if needed do other things you can do before the data is fetched
this.ClearTable();

// once you have nothing meaningful to do, await for your data
MyData fetchedData = await fetchDataTask;
this.ProcessData(fetchedData);

// finished:
this.ShowBusy(false); // remove picture box

// continue while opening:
    using (var sqlCommand = new SqlCommand(...))
    {
        cmd.Parameters.AddWithValue(...);

        // before executing the query: wait until OpenAsync finished:
        await taskOpen;

        // read the data. If nothing to do: await, otherwise use Task similar to Open
        SqlDataReader dataReader = await cmd.ExecuteReaderAsync();
        foreach (var row in dataReader)
        {
            ... (some Await with GetFieldValueAsync
        }
    }
}