collectionDef.exists()

Learn: Collections

Test if a collection exists.

Signature

exists() => Boolean

Description

Tests if a collection definition, represented as a Collection document, exists.

Collection documents are FQL versions of a database’s FSL collection schema. Collection documents have the CollectionDef type. See Collections.

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:

Collection.byName("Category").exists() // true

Collection.byName("Category") != null  // true

Key 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

Parameters

None

Return value

Type Description

Boolean

If true, the Collection document exists. If false, the Collection document doesn’t exist.

Examples

Collection.byName("Product").exists()
true
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