1. Create a link to the text file on disk (table A).
2. Delete all records from the database table (table B).
3. Import (append) records from table A to table B.
However, before you run any code that deletes all records from your table, you should take some precautions. For example, what will you do if the text file is damaged and you've all ready deleted everything from table B?
I would make a backup copy of table B first. Then, if necessary, you can restore the data from the backup copy to table B.
Randy