Firestore -如何在数据库中自动递减整数值？

const docRef = firestore.collection('your_collection').doc('your_document');

firestore.runTransaction(transaction => {
  return transaction.get(docRef).then(doc => {
    if (!doc.exists) {
      throw new Error('Document does not exist!');
    }

    const currentValue = doc.data().your_integer_field;
    const newValue = currentValue - 1;

    transaction.update(docRef, { your_integer_field: newValue });
  });
}).then(() => {
  console.log('Transaction successfully committed!');
}).catch(error => {
  console.log('Transaction failed: ', error);
});