如何更新mongodb数组值 [英] How to update mongodb array values

问题描述

我有一个像这样存储在 mongodb 中的文档

I have a document stored in mongodb like this

"Fiction" : [
           {
                   "SNo": "1",
                   "authorName" : "Enid Blyton",
                   "bookName" : "Secret series",
                   "Amount" : 115
           },
           {
                   "SNo": "2",
                   "authorName" : "Enid Blyton",
                   "bookName" : "Mystery series",
                   "Amount" : 150
           }
   ]

我想将金额从 115 更新为 135.

I would like to update the amount from 115 to 135.

我尝试像这样更新值.

db.fiction.update({"Fiction.SNo":"1"},{$set:{"Fiction.Amount":135}})

但我收到一个错误.

错误是

cannot use the part (Fiction of Fiction.Amount) to traverse the element 

任何人都可以帮忙解决这个问题，我需要实现它才能从 python 中工作.

Can anyone help on this, I need to implement this to work from python.

推荐答案

使用 $ positional 操作符在您的更新中，因为它标识了要更新的数组中的元素，而无需明确指定其在数组中的位置:

Use the $ positional operator in your update as this identifies the element in an array to update without explicitly specifying the its position in the array:

db.fiction.update({"Fiction.SNo":"1"},{$set:{"Fiction.$.Amount":135}})

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