Reference documentation and code samples for the Cloud Datastore Client class ReadOnlyTransaction.
Represents a Read-Only Cloud Datastore Transaction.
Read-Only Transactions allow you to execute one or more reads at the current, consistent state of Cloud Datastore at the time the transaction started.
Read-Only Transactions in Google Cloud PHP support rollback operations, but do not support commit. It should be considered best practice to rollback read-only transactions when you have finished using them.
Transactions are an optional feature of Google Cloud Datastore. Queries, lookups and mutations can be executed outside of a Transaction from Google\Cloud\Datastore\DatastoreClient.
Example:
use Google\Cloud\Datastore\DatastoreClient;
$datastore = new DatastoreClient();
$transaction = $datastore->readOnlyTransaction();
// Read-Only Transactions should be rolled back when they are no longer needed.
$key = $datastore->key('Users', 'Bob');
$userData = $transaction->lookup($key);
$transaction->rollback();