How to update mongodb array values

Question

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
           }
   ]

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

I tried to update the value like this.

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

But I get a error.

The error is

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

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

db.fiction.update({"SNo":"1"},{$set:{"Amount":135}}) – Sundar Singh Jan 05 '16 at 06:50 — Sundar Singh, Jan 05 '16 at 06:50

score 1 · Accepted Answer · answered Jan 05 '16 at 06:41

1

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}})

answered Jan 05 '16 at 06:41

chridam

100,957
23
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score 1 · Answer 2 · answered Jan 05 '16 at 07:11

1

The $ operator is used to iterate through the array list while updating.

Your query would be : db.Fiction.update({"Fiction.SNo":"1"},{$set:{"Fiction.$.Amount" : 135}})

answered Jan 05 '16 at 07:11

Suhas Shelar

963
2
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How to update mongodb array values

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