Retrieving multiple emails addresses for single contact on table join

[eluser]Andy UK[/eluser]
Hello all!

What's the best practice for retrieving multiple records from a second table on a join? I've just had to normalise customer emails into a separate table so I can permit multiple emails, select primary email, etc. Beforehand there was just a single email field in the contact table. I need to return all the email addresses for a contact when querying for the contact info.

I've read about a CONCAT function for MySQL that returns multiple values in a comma separated list. I guess another option would be to create a separate query to get the emails and run through that. For a single contact that should be easy as anything, whereas for a list of contacts I would have to loop through all the contacts, query the database each time for emails and add them to an array with a key equal to the contact id.

So those are the two ways i've come across. But since this must be such a common requirement, can anyone tell me what they consider to be the best way to do it?

Cheers!