如何将子集合添加到 firestore 中的子集合，反应应用程序

Question

I create subcollection of budgets in collection of users like this:

const addBudget = async (budget: Budget, userId: string) => {
  await addDoc(collection(db, 'users', userId, 'budgets'), { name: budget.name, max: budget.max });
};

The id of the budget is auto generated, but then I want to add another subcollection in budgets:

const addExpense = async (expense: Expense, userId: string) => {
  await addDoc(collection(db, 'users', userId, 'budgets', expense.budgetId /* auto generated id should be here here*/, 'expenses'), {
    description: expense.description,
    expenseValue: expense.expenseValue
  });
};

This is my structure in firestore, but it doesnt work right now, it creates new budget id of 1 and then creates subcollection of expenses:

How can I add this subcollection of expenses other way?

Answer 1

The addDoc function returns a DocumentReference . So if you capture that, you can read its id and use that to create another subcollection under it.

const budgetRef = await addDoc(collection(db, 'users', userId, 'budgets'), { name: budget.name, max: budget.max });
const budgetId = budgetRef.id;
...