Rest API to update a library item giving 400 error

Question

The code am using:

pnp.sp.web.getFolderByServerRelativeUrl("Shared%20Documents").files.getByName("test.jpg").getItem().then(item => {

      item.update({
          Title: "A Title",
          tag2: "My Other Value"
      });
    })

error : The property 'tag2' does not exist on type 'SP.Data.Shared_x0020_DocumentsItem'. Make sure to only use property names that are defined by the type.

NOTE: INTERNAL NAME DOES NOT WORK TOO!

Answer 1

I finally figured out the issue,i was using the wrong internal name. what i did was to go library setting-->select column-->Have a look at the link and look for field=something.

This was the wrong way of looking for the internal name. The correct way was

var item =pnp.sp.web.getFolderByServerRelativeUrl("Shared%20Documents").files.getByName("test.jpg")

console.log(item)

You then consult the body of item to identify the correct internal name.