ADO.NET Provider for AlloyDB

Build 23.0.8770

Querying with the DataAdapter

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

Using the AlloyDBDataAdapter

Use the adapter's Fill method to retrieve data from the data source. An empty DataTable instance is passed as an argument to the Fill method. When the method returns, the DataTable instance is populated with the queried data. Note that the AlloyDBDataAdapter is slower than the AlloyDBDataReader because the Fill method needs to retrieve all data from the data source before returning.

The following example selects the ShipName and ShipCity columns of the Orders table:

C#

string connectionString = "User=alloydb;Password=admin;Database=alloydb;Server=127.0.0.1;Port=5432";

using (AlloyDBConnection connection = new AlloyDBConnection(connectionString)) {
  AlloyDBDataAdapter dataAdapter = new AlloyDBDataAdapter(
  "SELECT ShipName, ShipCity FROM \"alloydb\".\"schema01\".Orders", connection);

  DataTable table = new DataTable();
  dataAdapter.Fill(table);

  Console.WriteLine("Contents of Orders.");

  foreach (DataRow row in table.Rows) {
    Console.WriteLine("{0}: {1}", row["ShipName"], row["ShipCity"]);
  }
}

VB.NET

Dim connectionString As String = "User=alloydb;Password=admin;Database=alloydb;Server=127.0.0.1;Port=5432"

Using connection As New AlloyDBConnection(connectionString)
  Dim dataAdapter As New AlloyDBDataAdapter("SELECT ShipName, ShipCity FROM \"alloydb\".\"schema01\".Orders", connection)

  Dim table As New DataTable()
  dataAdapter.Fill(table)

  Console.WriteLine("Contents of Orders.")

  For Each row As DataRow In table.Rows
    Console.WriteLine("{0}: {1}", row("ShipName"), row("ShipCity"))
  Next
End Using

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Build 23.0.8770