[Home](./index.md) > [@firebase/firestore](./firestore.md) > [/](./firestore_.md) > [Transaction](./firestore_.transaction.md) > [update](./firestore_.transaction.update.md) ## Transaction.update() method Signature: ```typescript update(documentRef: DocumentReference, data: UpdateData): this; ``` ## Parameters | Parameter | Type | Description | | --- | --- | --- | | documentRef | [DocumentReference](./firestore_.documentreference.md)<unknown> | | | data | [UpdateData](./firestore_.updatedata.md) | | Returns: this