Collection.firstWhere()

Get the first matching accessible collection.

Signature

Collection.firstWhere(predicate: () => Boolean)): CollectionDef | NullCollectionDef

Collection.firstWhere(predicate: (val: Collection) => Boolean)): CollectionDef | NullCollectionDef

Description

Each collection in a Fauna database is represented by a collection object. This method returns the first accessible collection object that matches the predicate function. When no matching collections exist or are accessible, returns null.

The predicate function must return a Boolean.

Parameters

Parameter Type Required Description

predicate

Function

Yes

Anonymous function that compares values in each collection document and returns true for matches or false for mismatches.

predicate parameters:

Parameter Type Required Description

val

Collection

Collection object to compare. If omitted, use dot notation to access collection properties.

Return value

One of:

Type Description

CollectionDef

First accessible collection definition document matching the predicate function.

NullCollectionDef

No collections match the predicate function or all matching collections are inaccessible.

Examples

Collection.firstWhere(.name.includes('te'))
{
  name: "Letter",
  coll: Collection,
  ts: Time("2022-10-25T21:01:19.310Z")
}

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