Querying with the DataReader
The CData ADO.NET Provider for SendGrid implements two ADO.NET interfaces you can use to retrieve data from SendGrid: SendGridDataAdapter and SendGridDataReader objects. Whereas SendGridDataAdapter objects retrieve a single result set of all the data that matches a query, SendGridDataReader objects fetch data in subset increments as needed.
Using the SendGridDataReader
The SendGridDataReader retrieves data faster than the SendGridDataAdapter because it can retrieve data in pages. As you read data from the SendGridDataReader, it periodically requests the next page of results from the data source, if required. This causes results to be returned at a faster rate. The following example selects all the columns from the MarketingCampaigns table:
C#
string connectionString = "APIKey=abc123;"; using (SendGridConnection connection = new SendGridConnection(connectionString)) { SendGridCommand cmd = new SendGridCommand("SELECT * FROM MarketingCampaigns", connection); SendGridDataReader rdr = cmd.ExecuteReader(); while (rdr.Read()) { Console.WriteLine(String.Format("\t{0} --> \t\t{1}", rdr["Title"], rdr["Subject"])); } }
VB.NET
Dim connectionString As String = "APIKey=abc123;" Using connection As New SendGridConnection(connectionString) Dim cmd As New SendGridCommand("SELECT * FROM MarketingCampaigns", connection) Dim rdr As SendGridDataReader = cmd.ExecuteReader() While rdr.Read() Console.WriteLine([String].Format(vbTab & "{0} --> " & vbTab & vbTab & "{1}", rdr("Title"), rdr("Subject"))) End While End Using