Querying with the DataAdapter
The CData ADO.NET Provider for CockroachDB implements two ADO.NET interfaces you can use to retrieve data from CockroachDB: CockroachDBDataAdapter and CockroachDBDataReader objects. Whereas CockroachDBDataAdapter objects retrieve a single result set of all the data that matches a query, CockroachDBDataReader objects fetch data in subset increments as needed.
Using the CockroachDBDataAdapter
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 CockroachDBDataAdapter is slower than the CockroachDBDataReader 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=root;Password=root;Database=system;Server=localhost;Port=26257"; using (CockroachDBConnection connection = new CockroachDBConnection(connectionString)) { CockroachDBDataAdapter dataAdapter = new CockroachDBDataAdapter( "SELECT ShipName, ShipCity FROM \"defaultdb\".\"public\".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=root;Password=root;Database=system;Server=localhost;Port=26257" Using connection As New CockroachDBConnection(connectionString) Dim dataAdapter As New CockroachDBDataAdapter("SELECT ShipName, ShipCity FROM \"defaultdb\".\"public\".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