How to get a database connection

[open-schnick]

I wanted to know wheter or not it is possible to get a connection from the pool without the guard of an endpoint.
For example i want to access the database in a function that is not called from an endpoint.
Is there a way to get a connection from the pool?

[ELD]

The answer varies, a little, depending on whether you're using synchronous or asynchronous databases.

For rocket_sync_db_pools, there's a get_one method that's implemented on the database type. The one caveat is that it requires a Rocket instance to fetch the connection. That can be a little tricky getting an instance if the method is being called outside of a handler or other Rocket-related code.
Docs: https://api.rocket.rs/v0.5-rc/rocket_sync_db_pools/attr.database.html (not the async fn get_one(...) ... doc item)

For rocket_db_pools, there's a fetch method that returns the database instance. From there, you can access the inner type, grab a connection, and use it as you please. This also has the same caveat that you need a Rocket instance to fetch the database.
Docs: https://api.rocket.rs/v0.5-rc/rocket_db_pools/trait.Database.html#method.fetch

[open-schnick]

Ok thank you.
Is there a way to get a rocket instance available for all threads everywhere?
Do you have a code snippet or an example?