public void InsertRow(string pgConnectionString)
{
  // If the connection string is empty, use default.
  if(pgConnectionString == "")
  {
    pgConnectionString = 
        "host=server;database=test;user id=postgres;";
  }
  PgSqlConnection myConn = new PgSqlConnection(pgConnectionString);
  string myInsertQuery = "INSERT INTO DEPT VALUES (50,'Development','Philadelphia')";
  PgSqlCommand pgCommand = new PgSqlCommand(myInsertQuery);
  pgCommand.Connection = myConn;
  myConn.Open();
  try
  {
    pgCommand.ExecuteNonQuery();
  }
  finally
  {
    myConn.Close();
  }
}