Update/import values in multi-lookup field for existing records

Update/import values in multi-lookup field for existing records

Hi guys, 

I have an issue: 

I created a custom module and added a multi-lookup for that custom module in the contacts-module. I now have a few csv-files which contain the information of the existing contact (e-mail) and only one value that should be imported into that multi-lookup field (group name).  

I now have 2 issues:  

  1. I cannot import values into a lookup field.  

  1. Even if I could it would always overwrite the new values of the new excel file, but it should actually attach the values. For example, in one file I have customer A with group A and in the other file customer A with group B. It should be that after the import customer A has both values group A and group B in that field and not that after the second import group A gets overwritten with group B.  

 

Does anybody have a solution for that?  

 

Cheers, 
Elias