Há algumas boas informações aqui:Criar um banco de dados SQL Server Compact Edition com C#
string connectionString = "DataSource=\"test.sdf\"; Password=\"mypassword\"";
SqlCeEngine en = new SqlCeEngine(connectionString);
en.CreateDatabase();
string connectionString = "DataSource=\"test.sdf\"; Password=\"mypassword\"";
SqlCeEngine en = new SqlCeEngine(connectionString);
en.CreateDatabase();