java - 无法从 firestore 中删除字段

Question

我无法从 firestore 中删除字段

else if(starPosition == 0){
   Map<String, Object> deleteRating = new HashMap<>();
   deleteRating.put(inititalRating + "_star", documentSnapshot.getLong(inititalRating + "_star") - 1);
   deleteRating.put("average_rating", String.valueOf(calculateAverageRating(starPosition-inititalRating,true)));
   deleteRating.put("total_ratings", documentSnapshot.getLong("total_ratings") - 1);

   firebaseFirestore.collection("PRODUCTS").document(productID)
           .update(deleteRating).addOnCompleteListener(new OnCompleteListener<Void>() {
       @Override
       public void onComplete(@NonNull Task<Void> task) {
           if (task.isSuccessful()) {
               Map<String, Object> ratingUpdate = new HashMap<>();
               ratingUpdate.put("list_size", DBqueries.myRatedIds.size() - 1);
               ratingUpdate.put("product_ID_" + DBqueries.myRatedIds.size(), FieldValue.delete());
               ratingUpdate.put("rating_" + DBqueries.myRatedIds.size(), FieldValue.delete());

               firebaseFirestore.collection("USERS").document(currentUser.getUid()).collection("USER_DATA").document("MY_RATINGS")
                       .update(ratingUpdate).addOnCompleteListener(new OnCompleteListener<Void>() {
                   @Override
                   public void onComplete(@NonNull Task<Void> task) {

                   }
               });


           }
       }
   });    

}

该字段未删除，我在这里使用 FieldValue.delete()

Answer 1

你的柜台少了一位。你运行:

   Map<String, Object> ratingUpdate = new HashMap<>();
   ratingUpdate.put("list_size", DBqueries.myRatedIds.size() - 1);
   ratingUpdate.put("product_ID_" + DBqueries.myRatedIds.size(), FieldValue.delete());
   ratingUpdate.put("rating_" + DBqueries.myRatedIds.size(), FieldValue.delete());

   firebaseFirestore.collection("USERS").document(currentUser.getUid()).collection("USER_DATA").document("MY_RATINGS")

由于屏幕截图显示 list_size 为 0，这意味着 DBqueries.myRatedIds.size() 为 1。因此您要删除 product_ID_1 和 rating_1 字段，这些字段确实不存在/不再存在于文档中。

如果您想删除 0 索引字段，则还需要使用 DBqueries.myRatedIds.size() - 1。