如何在 Web v9 中使用“where”子句从 Firestore 集合中删除文档

Question

I'm struggling to complete the following code:

const myCollection = collection(db, 'myCollection');
const mycollectionQuery = query(myCollection, where("field1", "==", "xyz"));
myCollectionSnapshot.forEach((doc) => {
     deleteDoc(?);
});

Advice on what to supply inside the deleteDoc call would be much appreciated. I was pretty confident it would be doc.id , but this returns a "Cannot use 'in' operator to search for '_delegate' in undefined" error message

Answer 1

In V9, the deleteDoc() method takes a DocumentReference, as documented here .

As you can see from the documentation of your forEach() , the doc variable will be a QueryDocumentSnapshot, that is a specialization of DocumentSnapshot. It means that, if you want to retrieve the DocumentReference for your doc , you just need to reference to it via doc.ref .

In other words, to delete the document you'll need to do this:

myCollectionSnapshot.forEach((doc) => {
     deleteDoc(doc.ref);
});

Answer 2

This is how you delete a document from cloud firestore:

deleteDoc(doc(db, "reference"))

So, the complete code is:

const myCollection = collection(db, 'myCollection');
const mycollectionQuery = query(myCollection, where("field1", "==", "xyz"));
myCollectionSnapshot.forEach((doc) => {
     deleteDoc(doc(db, doc.ref));
});