So I'm a newbie in using firebase real time database and I can't delete products key child with id specified.

I've tried this approach but it didn't yield any success:

removeProductById = async (id, user) => {
    const userProductRef = db.ref(`products/product`);
    try{
        var query = userProductRef.orderByChild('id').equalTo(id);
        query.remove()             
        })

    }catch(error){
        console.log(`The error has occured ${error.message}`)
    }
}

So I wanna know how can one delete any tipe of key by whatever value they specify. Thank you in advance, you have always helped me guys.

CodePudding user response：

There are two problems here:

1. Your query doesn't match the nodes you want delete.
2. Firebase doesn't support delete-queries.

Your query doesn't match the nodes you want delete

Your query starts at a node products/product, which doesn't exist in your database, and then orders/filters the id property of each child node.

What you want instead is to start at the products node, and then order/filter on its product/id property of each child node:

In code:

const userProductRef = db.ref(`products`);
var query = userProductRef.orderByChild('product/id').equalTo(id);

Don't forget that you'll need to define an index for product/id for this on the products level in your rules.

Firebase doesn't support delete-queries

You can't simply pass the query and delete instruction to Firebase. To write a node in the database, you'll need to know the entire path to that node.

So you'll need to:

1. Execute the a query.
2. Loop over the results in your application code.
3. Delete each matching node individually or in a multi-path update.

With the query above, that'd be:

query.once("value").then((snapshot) => {
  snapshot.forEach((child) => {
    child.ref.remove();
  });
})

Or with a multi-path/batch update:

query.once("value").then((snapshot) => {
  let updates = {};
  snapshot.forEach((child) => {
    updates[child.key] = null;
  });
  ref.update(updates);
})