im currently doing a migration page where my user will provide the csv file so i could load into my table. problem is this data loading is using apex collection thus i know columns are limited but i forgot how much.(probably 40 something).
so i decided to split the csv with both of the files having a common column which is a key. so im guessing two files can be linked using this key. however when i upload second file, it will still do an insert action instead of update. how do i update? is there anything i need to set or enable?
just to check i tried uploading the csv..and then changed some contents in it and re upload..even if i do that.it will still insert instead of update. Can anyone share how i can update? this is really important because i've got a lot of columns to upload. so the best way in my situation is to split files.