CiviCRM Community Forums (archive)

I need to import a number of contacts from an old database (not really even a database!) where in some cases individuals were listed as pairs, with 2 first and 1 last name, and sometimes 2 first and 2 last names -but a single, shared email address.
Before experimenting with 'import contacts' I broke the pairs out into 2 'rows' in a CSV, with one first,last name and email address plus an external identifier so I could tell these were pairs.  When attempting to import them as 'individuals' I took just a few and selected 'no duplicate checking' - this resulted in a trace (not just a nice error.csv file). Is this is a problem for the Civi database (civicrm_email table) and I need to apply 1 email address to one individual contact - and make a second pass/import to treat the 2nd contact as a 'household'? 
Any suggestion as to how this *should* be mapped (not just how to make it work and allow duplicate emails for individuals)? I know that I can define a 'relationship' (spouse) btwn contacts, but how to import them, using a single, shared email?
As an example if the above wasn't clear, I have 'Amy and Andy Jones', using 'ajones@gmail.com' and same address, in the CSV they are 'Amy Jones','ajones@gmail.com'  and 'Andy Jones','ajones@gmail.com'

Thanks, Joanne, I took a look at the civicrm_contact table definition, and you are right about my error - the 'external identifier' has to be unique.
Now  I can import the 2 'individuals' who are related as spouses, and if I don't 'check for duplicates'  on import(ie, make use of strict de-duping on email address) I can import them into Civi as 'individual' contacts, and email (civicrm_email.email) isn't required to be unique.

Now, even though there aren't database constraints to prevent duplicate emails, should I NOT be sharing email addresses between 2 individuals? It seems that since the 'de-duping' for contacts (in Find & Merge as well as when users register for events, or contribute) hinges on email, it is a design mistake to allow  2 'individuals' to share 1 email address. If they only have one email address between them, should one of the 2  have 'the email address' and the other just be identified in a relationship of 'spouse' to the first?

It is the case that they may need to register for events (or contribute to a campaign) so I believe that email needs to be unique; each contact is meant to be a 'unique' person; since names can be unreliable email addresses are probably the best 'identifiers'. I think that indeed, it would be problematic on any kind of contact/participant search, if you search by email, and def. when a person 'registers' for an event, the 'strict' de-dupe rule (on email) will be an issue.
Thanks for replying, Joanne!