Rename fields machine name in Drupal 7

What:

Drupal 7

Problem:

You want to change fields machine names in Drupal 7.

Solution:

If you don't have any content then recommended way is to delete a field and crate a new one, but what if you have already some articles?

Export your database:

mysqldump -u [username] -p [database] > backup.sql

Use sed to replace  your old field name with a new one, make sure that you use the same number of characters in a new name, otherwise it will not work.

sed -i 's/field_random_name/field_better_name/g' baskup.sql

Import it back:

mysql -u [username] -p [database] < backup.sql