accessProvider.exists()
| Learn: Access providers |
|---|
Test if an access provider exists.
Description
Tests if an access provider,
represented as an
AccessProvider document,
exists.
AccessProvider documents are FQL versions of a database’s FSL
access provider schema.
AccessProvider documents have the AccessProvider type. See
Access providers.
Staged schema
If a database has staged schema, this method interacts with the database’s staged schema, not the active schema.
exists() vs. null comparisons
You can use either exists() or a null comparison (== null or != null) to
check the existence or validity of a value. For example:
AccessProvider.byName("someIssuer").exists() // true
AccessProvider.byName("someIssuer") != null // trueKey differences:
-
exists()returns an error if called on an unsupported value. -
Null comparisons do not throw errors and work safely on any value.
For example:
// Declare an object. Objects don't support
// an `exists()` method.
let object = { a: "Foo", b: "Bar" }
object.exists() // Returns `invalid_query` error
object != null // Returns true