CiviCRM Community Forums (archive)

Currently forcing a merge will add any new information from the 'other' contact on to the 'main' contact. Any emails, phones etc. are also 'added' - no overwrites. If there are any conflicts on the records (differing data on the same field) then the information on the 'main' contact is preserved.

There's an example here:
https://issues.civicrm.org/jira/browse/CRM-18338

There's also a ticket about getting more control in the dedupe API:
https://issues.civicrm.org/jira/browse/CRM-12421

However, I think the 'force' option could be cleverer about how it handles merges - for example taking into account which contact was 'last updated' most recently; and somehow reducing the number of duplicate phones/emails with the same type when merging - potentially by overwriting rather than adding them.

Eileen suggested a working group on this for the next release cycle - so if anyone else is heavily into the 'deduping' functionality of Civi then shout and maybe we can take a look at this in more detail. Obviously changes in this area are potentially quite dangerous/impactful so that's another reason for reaching out.

(This was originally posted on the civicrm-dev mailing list, but I think the forum is a good place to continue the discussion)