Sometimes when you upgrade your application the new version does not work correctly, and you need to downgrade. When you are unlucky you did some changes in your database that cannot be undone. In that case you need to restore the database from a backup, which is usually quite cumbersome and time-consuming. How nice would it be if you could just run an undo script which is much more light weight. This blog describes how you can do that using Flyway.

Nushell has the in operator to check if a value is an element of list. With the same in operator you can check if a string is a substring of another string. And finally you can use the in operator to check if a key is in a record. When you use the operator the value you want to check is defined before the operator and the list, other string or record is defined after the operator.
The not-in operator is the opposite of the in operator and checks if a value is not in list or other string or key in a record.
It is also possible to use the has and not-has operators to do the same checks, but the value you want to check is set after the operator. The list, other string or record is set before the operator.