Extract lastname from "lastname firstname"

[David O'Meara]

Just wrote some code at work to solve this problem, and I sound the solution quite pleasing and elegant to my eye
I'll drop the problem and see if anyone gets the same thing. (I'm running the data conversion on several thousand rows as I write)
In the database, names are stored as a single field NAME, and this is in the form "<lastname> <firstname>" (space separated). We want to try to separate it into two fields.
The firstname can be more than word, but we assume that anything after the last name is the firstname. The difficulty is finding the lastname. We assume that any last name that consists of several words is prefixed by one of: di, de, du, da, mac, van den, van der, van, de la.
Then the next name is part of the last name too.
Well, I enjoyed it, anyway. :roll:

[Jim Yingst]

import java.util.regex.*;
public class LastName
{
  private static final String prefixes = "(?:d[aeiu]|de la|mac|van(?: de[nr])?)";
  //private static final String prefixes = "(?:di|de|du|da|mac|van den|van der|van|de la)";
  private static final Pattern pat = Pattern.compile("((?:" + prefixes + " *)?[^ ]+) *(.*)");
  public static void parse(String input)
  {
    System.out.println("\nInput:\t<" + input +">");
    Matcher m = pat.matcher(input);
    if (m.matches())
    {
      System.out.println("Last:\t<" + m.group(1) + ">");
      System.out.println("First:\t<" + m.group(2) + ">");
    }
    else
      System.out.println("No match");
  }
  public static void main(String[] args)
  {
    parse("O'Meara David");
    parse("de Queiroz Marilyn");
    parse("Yingst Jim");
    parse("Sting");
    parse("Romijn-Stamos Rebecca");
  }
}

You might want to add "del", "della", "de los", "de las", and "mc". And who knows what else if we move past European languages.
[ June 03, 2003: Message edited by: Jim Yingst ]

[SJ Adnams]

(an aside)
our database holds european data. we have a 3 columns - firstname, lastname, fullname.
There are so many exceptions, and ways in how people like to be referred that we have to do this.

[David Hibbs]

Originally posted by Simon Lee:
(an aside)
our database holds european data. we have a 3 columns - firstname, lastname, fullname.
There are so many exceptions, and ways in how people like to be referred that we have to do this.

This is why there are commercial packages especially for the purpose of data cleansing. A quick and dirty way is fine, but getting it right is another thing entirely.