Varia

Microsoft Database Engines

SQL Server
SQL Server Express
SQL Server Compact
LocalDB: LocalDB is the full SQL Server Express engine, but invoked directly from the client provider. It is a replacement of the current “User Instance” feature in SQL Server Express.

Comparison
http://msdn.microsoft.com/en-us/library/vstudio/ms233817.aspx

Convert timestamp to string

/// <summary>
/// Converts a timestamp to a hexadecimal string proceeded by 0x (to show it's a hexadecimal value)
/// </summary>
/// <param name="timestamp">The timestamp to be converted</param>
/// <returns>A hexadecimal string (proceeded by 0x)</returns>
public static string TimestampToString(System.Data.Linq.Binary timestamp)
{
  Byte[] bytes;
  string ts = "";
  bytes = timestamp.ToArray();
  foreach (Byte b in bytes)
  {
    ts += b.ToString("X").PadLeft(2, Convert.ToChar("0"));
  }
  return "0x" + ts; // This will not work with the function below, only to show. Use 'return ts;' to use with function below
}

Convert string to timestamp

public static System.Data.Linq.Binary StringToTimestamp(string s)
{
  char[] arr = s.ToCharArray();
  byte[] result = new byte[8];
  for (int i = 0; i < 8; i++)
  {
    string t = string.Format("{0}{1}", arr[(i * 2)], arr[(i * 2) + 1]);
    result[i] = byte.Parse(t, System.Globalization.NumberStyles.HexNumber);
  }
  return result;
}

To support rollback, you need to enable transactions

Switch on transactions (MSDTC)

Configuratiescherm (Control Panel) - Systeembeheer (Administrative Tools) - Component services
In Component services: go to Component services - Computers - Deze computer
Right click on Deze computer, choose Eigenschappen.
Go to the tab MSDTC
Click on Beveiligingsconfiguratie.
DTC-netwerktoegang: selected
Externe clients toestaan: selected, Extern beheer toestaan: selected
Inkomend verkeer toestaan: selected, Uitgaand verkeer toestaan: selected
Select Wederzijdse verificatie is vereist
TIP-transacties: selected
XA-transacties inschakelen: not selected (update 2013-08-22: start test with this setting selected)

Windows 7:

In Component services: go to Component services - Computers - Mijn computer - Distributed Transaction Coordinator - Lokale DTC
Right click on Lokale DTC, choose Eigenschappen.
Go to the tab Beveiliging.
See above for settings.