Need to update value in SQL records with contents from external files

I have XML files in a folder. Each file has an associated record in a MySQL table with a field called 'xml'. I need to replace the contents of that field with the contents that are in the file. There is a field in the record that matches the file name of the xml file, so I'm looking for the most straight forward way to do this?

I'm assuming this is not possible with only a SQL statement that reaches out for a file name and uses the contents to update the field, but that would be my preference. Using some external script would be the next step, but that introduces some internal process complexities I'd like to avoid if at all possible.