Hello,

I have set up an External Content type via SharePoint Designer. I used it to create an external list on my site, and I used that external list to create a lookup column that could leverage the data in a document library. The External Content Type is connexted to an SQL Server view. The look up column is based on a unique column from the view, and it also brings a long a few additional fields.

I have successfully used the lookup column in a document library. When I upload a new file, I can select data that is clearly current. However, the documents I uploaded previously still show old data. When I hit the refresh button for my lookup column, it takes only a second or two to update. However, the data does not up date. So I am stuck with my documents displaying inaccurate data unless I edit them one by one.

Does anyone know why my Refresh isn't working?

External data in your external list will be auto refreshed, but if you create a lookup column from external list, it saves the data when you created the item or updates the data when you update it. 

I believe that's how it works. I may be wrong!

There is a Refresh External Data button for the library, but that's what isn't working. I am trying to figure out why it isn't working, when I've seen plenty of documentation saying it should. When you press the button it even asks you if you want to do all folders, or just the current one, then it warns you that the operation may take a long time.

https://support.office.com/en-us/article/Create-and-update-an-external-data-column-in-a-list-or-library-44eff2c5-8051-489d-989c-f5d09f527aee