Eureka! There's still way to migrate this custom list with attachments. :)
Here's what what i did in my 5000+ data w/ attachments custom list:
- Migrate all first the data from Old to New Custom List by copying data from Old Custom List and pasting it to the New Custom List via Data Sheet View.
- Create an excel spreadsheet and copy paste the ID column of the Old CustomList Data and the new ID of the new CustomList Migrated Data.
OLD-ID | NEW-ID
345 | 1
346 | 2
- Open existing Document Library on the old site , then navigate to your CustomList where you will see attachments folder. Inside the attachments folder resides all attachments folder named using the ID column used in the CustomList.
Attachments > 345 > sample.pdf,test.jpg
> 345 > abc.xlsx
Copy Paste the attachments folder on your Local Machine and create an application that will rename the old folder to new folder name based on the excel spreadsheet.
Run your program then after that you can now navigate to the Attachments folder of the new site then copy paste all the items renamed on your local machine inside the new Custom List attachments folder.
After that, Navigate now on your New Custom List and its now populated with their respective attachments file.
You now have successfully migrated Custom List with attachments. :)
Hope this help other folks having same problem migrating custom list w/ attachments.