The CData ADO.NET Provider for Azure Synapse implements two ADO.NET interfaces you can use to retrieve data from Azure Synapse: AzureSynapseDataAdapter and AzureSynapseDataReader objects. Whereas AzureSynapseDataAdapter objects retrieve a single result set of all the data that matches a query, AzureSynapseDataReader objects fetch data in subset increments as needed.

Using the AzureSynapseDataReader

The AzureSynapseDataReader retrieves data faster than the AzureSynapseDataAdapter because it can retrieve data in pages. As you read data from the AzureSynapseDataReader, 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 "SampleDB"."Sample".Products table:

C#

string connectionString = "user=myuser;password=mypassword;Server=localhost;Database=Northwind;";

using (AzureSynapseConnection connection = new AzureSynapseConnection(connectionString)) {
  AzureSynapseCommand cmd = new AzureSynapseCommand("SELECT * FROM \"SampleDB\".\"Sample\".Products", connection);
  
  AzureSynapseDataReader rdr = cmd.ExecuteReader();

  while (rdr.Read()) {
    Console.WriteLine(String.Format("\t{0} --> \t\t{1}", rdr["Id"], rdr["ProductName"]));
  }
}

VB.NET

Dim connectionString As String = "user=myuser;password=mypassword;Server=localhost;Database=Northwind;"

Using connection As New AzureSynapseConnection(connectionString)
  Dim cmd As New AzureSynapseCommand("SELECT * FROM \"SampleDB\".\"Sample\".Products", connection)

  Dim rdr As AzureSynapseDataReader = cmd.ExecuteReader()

  While rdr.Read()
    Console.WriteLine([String].Format(vbTab & "{0} --> " & vbTab & vbTab & "{1}", rdr("Id"), rdr("ProductName")))
  End While
End Using