How to use select in storage policy?

[wwsalmon]

I'm trying to create a policy that grants access to a folder to all users with a username that is the same as the folder name (non-unique usernames). I have a user table that contains rows with UUIDs and usernames, so I've tried to set up a bucket policy like this:

(storage.foldername(name)) [ 1 ] = (
  select
    username
  from
    user
  where
    uuid = auth.uid():: text
)

However, I get the error "Error adding policy: column "username" does not exist."

Any pointers on what I'm doing wrong and how to fix?

[wwsalmon]

Looks like user being a reserved keyword was causing problems, but putting it in quotes didn't fix it:

(storage.foldername(name)) [ 1 ] = (
  SELECT
    username
  FROM
    'user'
  WHERE
    uuid:: text = auth.uid():: text
)

results in the error "Error adding policy: syntax error at or near "'user'""

[wwsalmon]

Renamed my user table to app_user and now the following code works

(
  (storage.foldername(name)) [ 1 ] = (
    SELECT
      app_user.username
    FROM
      app_user
    WHERE
      ((app_user.uuid):: text = (uid()):: text)
  )
)