Why is COALESCE() result an Option ?

[axeld-galadrim]

If I have the following query:

select coalesce(name, "No username")
from users
limit 1

and I want to query it using query_scalar! for example, with fetch_one, the result will STILL be an
Option<String> and not a String.
(If name is a VARCHAR that can be null)

Is there a reason for that ?
Will this be fixed any time soon ?

[pxp9]

I think COALESCE will be always an Option<T> because the function itself returns first argument that is not NULL according PostgreSQL docs

What if all arguments of COALESCE are NULL ? this will return NULL. So you need a type that handles the possibility of being NULL or not, that's why COALESCE will be always Option<T>.

I think you should decode it as Option<String> and use unwrap as you always know that will not be None variant.

[pronebird]

@pxp9 however second argument in the provided example is not NULL Is there any way to tell sqlx that the argument cannot be NULL?