Angular & Firebase 实时数据库。 如何让孩子知道其 id 属性但不知道其父节点

Question

My Database is like this

I can get to cart part on my own and I can even delete the product from cart.. if I type in the auto generated id manually.. Honestly, I have been trying to do this for 2 days now. I researched every stackoverflow question related to firebase database but I still couldn't figure it out.

I get to cart like this: firebase.database().ref('/' + account[0] + '_user' + '/cart')

But I can't go further.. assume that I am also providing product that needs to get deleted and you can access its id through item.id

Right now if you click on delete button the whole cart gets deleted.

Answer 1

If you know the product/id property of the node to delete, you can use a query to order/filter the nodes and find the key of the one(s) you want to delete:

const cartRef = firebase.database().ref('/' + account[0] + '_user' + '/cart');

const itemQuery = cartRef.orderByChild("product/id").equalTo(3);

itemQuery.get().then((snapshot) => {
  snapshot.forEach((productSnapshot) => {
    console.log(productSnapshot.key, productSnapshot.child("product/id").val());
  })
}).catch((error) => {
  console.error(error);
})