How to delete documents that contain a certain value in one of the fields. Firestore, Flutter - flutter

Question

enter image description here
I have these documents, which contain data about each task I add to the list in my app.
child: StreamBuilder(
stream: _tasks.snapshots(),
builder: (context, AsyncSnapshot<QuerySnapshot> streamSnapshot) {
if (streamSnapshot.hasData) {
return ListView.builder(
itemCount: streamSnapshot.data!.docs.length,
itemBuilder: (context, index) {
final DocumentSnapshot documentSnapshot =
streamSnapshot.data!.docs[index];
return GestureDetector(
onLongPress: () => _update(documentSnapshot),
child: ListTile(
)
);
},
);
}
return const Center(
child: CircularProgressIndicator(),
);
},
),
I am using a stream builder to build the list. Each of the tasks have a checkmark and when i click it, It updates the value in firestore inside the IsDone field accordingly. I want to click a button outside the stream builder to delete the checked tasks. How do I loop through all the documents and find all the documents that contain the value true and delete them?
I tried this but im doing doing something wrong and it isnt changing anything:
void _delete() {
var docs = _tasks.doc().snapshots();
docs.forEach((doc){
if(doc.data()==true){
_tasks.doc(doc.id).delete();
}
});
ScaffoldMessenger.of(context).showSnackBar(const SnackBar(
content: Text('You have successfully deleted a product')));
}

Answer 1

var datas = await FirebaseCalls.firebaseFirestore
.collection("collection_id")
.where("status", isEqualTo: true)
.get();
datas.docs.forEach((element) {
FirebaseFirestore.instance
.collection("collection_id")
.doc(element.id)
.delete();
});
or you can do like this as well.
var datas =
await FirebaseCalls.firebaseFirestore.collection("collection_id").get();
datas.docs
.where((element) => element["status"] == true)
.toList()
.forEach((el) {
FirebaseFirestore.instance
.collection("collection_id")
.doc(el.id)
.delete();
});

Answer 2

You can delete by doing this below:
find the particular document as per your query and get its document and collection ID.
FirebaseFirestore.instance
.collection("collection_id")
.doc("doc_id")
.delete();