'Update unique nested array element in Mongodb

I have a very simple example from official documentation page:

Data:

   { item: "journal", instock: [ { warehouse: "A", qty: 5 }, { warehouse: "C", qty: 15 } ] },
   { item: "notebook", instock: [ { warehouse: "C", qty: 5 } ] },
   { item: "paper", instock: [ { warehouse: "A", qty: 60 }, { warehouse: "B", qty: 15 } ] }

I want to update quantity where item = "journal" and warehouse = "A".

Item is always unique, warehouse is always unique within array elements.

For example I tried queries like this:

collection.updateOne(
"{ \"item\": \"" + item + "\", \"instock.warehouse\": \"" + warehouse + "\" } } }", // find
"{ $set: { quantity: \"" + quantity + "\" } }" // update
)

Issue is always the query, for example this query returns all elements... I tried about 100 different other ones but nothing is working.

I am using embedded db for tests right now from flapdoodle, version 3_4.

javamongodbmongodb-query


Solution 1:[1]

You need to use positional operator

Playground

db.collection.update({
"instock.warehouse": "C",
  "item": "journal"
},
{
  $set: {
    "instock.$.qty": 10
  }
})

Sources

This article follows the attribution requirements of Stack Overflow and is licensed under CC BY-SA 3.0.

Source: Stack Overflow

Solution Source
Solution 1 Gibbs

Related Questions