I'm in a project using SharePoint Online and want to add a lookup column type, but when trying to relate it to a specific list, show me a few columns in the list which has more than 30 columns, I would know that this is due and if there is any solution, I thank you in advance for the help
1 Answer
Only Unique value columns can be added as Look Up column to another list. Make sure those missing columns have "Enforce Unique Values" checked.