MongoDB update Nested field - mongodb

Question

In MongoDB how do you use $set to update a nested value?
For example, consider a collection people with the following document:
{
_id: ObjectId("5a7e395e20a31e44e0e7e284"),
name: "a",
address: [{ street: "123", town: "bar" }]
}
How do I update the street field embedded in the address document from "123" to "Main Street"?

Answer 1

Thanks, but I found the solution :
db.collection.updateMany(
{ "address.street": "123" },
{ "$set": { "address.$[].street": "Main Street" } }
)

Answer 2

Use $set along with $ postion operator like this :
db.collection.update(
{ "address.street": "123" },
{ "$set": { "address.$.street": "Main Street" } }
)

Answer 3

You have to use $[<identifier>] (positionnal update operator) to update the address that match (here street="123" and town="bar")
Using this slightly different model (just added addresses to better understand) :
{
"_id" : ObjectId("5a7e395e20a31e44e0e7e284"),
"name" : "a",
"address" : [
{
"street" : "123",
"town" : "bar"
},
{
"street" : "Lower Street",
"town" : "bar"
},
{
"street" : "123",
"town" : "foo"
}
]
}
The query to apply :
db['01'].update(
{"_id" : ObjectId("5a7e395e20a31e44e0e7e284")},
{$set:{"address.$[current].street":"Main Street"}},
{ arrayFilters: [{current:{street:"123","town":"bar"}} ]}
)
Will result in :
{
"_id" : ObjectId("5a7e395e20a31e44e0e7e284"),
"name" : "a",
"address" : [
{
"street" : "Main Street",
"town" : "bar"
},
{
"street" : "Lower Street",
"town" : "bar"
},
{
"street" : "123",
"town" : "foo"
}
]
}