Updating field on import

[gaidys]

What is the best way to update a field while importing a .CSV file? I refer opportinities to a third party, identifying each one with its "Opportunity Name". This third party assigns its own code number to each opportunity, giving me back a list of these codes, associated with each Opportunity Name. I created a new field in the opportunities module to store the codes associated to the opportunities. But so far the only way I found to update this field was manually, what is evidently not the best way to do it. What I want to achieve is very simple: given a 2-column list of opportunies x third-party code numbers, I want to update the third-party code number in each opportunity, by means of its unique "Opportunity Name". Anyone?

[robertbmirth]

If you create a header with the .csv and make the header of your custom field the same as its database name (i.e. with '_c' appended) the you should be able to mass update using the import feature.

[gaidys]

The only effect of using xxx_c is getting automatic mapping of fields. Problem is that the opportunity module requires several other fields as mandatory on import, does not accept only the two columns, and does not present a "mass update" option (I'm using CE 5.5.2). How can it know it shall update existing records instead of creating new ones?