SQL Server BULK Insert with non standard NULL value

I 开发者_如何学Pythonhave a large CSV file with columns that support NULL but the value for NULL is "NA". How can I import this to SQL server without replacing those values with NULL?

Import it as the string NA. It isn't NULL. Nothing to worry about.

If the field is a *char then why not import the value as NA, and then run a bulk update setting the field to NULL after import?