How to update a one to many relationship MongoDB - mongodb

Question

If i have a Person collection that has many addresses, how can I insert multiple addresses that belong to a person? I know how to do it if it were a one to one relationship where I would simply do something like:
db.persons.update({_id: '12345'}, {$set: {'address': '12345 fake st'}})
However, that won't work for a one to many relationship since the person's address would get replaced every time someone adds an address to that person. Can someone help? Thank you in advance.

Answer 1

If you want a person to hold many addresses then you could make address an array and you could insert new addresses using the push operator.
db.persons.update(
{ "_id": "12345" },
{ "$push": { "address": "12345 fake st"}}
);
Your schema would then look like this:
{
"_id" : "12345",
"address" : [
"12345 fake st",
"6789 second st",
...
]
}
Of course you can make this as complex as required. So if you need to store extra information for each address, you can instead insert subdocuments into the address array.
{
"_id" : "12345",
"address" : [
{
"number" : "6789",
"street" : "second st",
"primary" : false
},
{
"number" : "12345",
"street" : "fake st",
"primary" : true
},
...
]
}
As noted in the comments, if you want to ensure that there are no duplicates in your array, you should use the $addToSet operator, which provides that functionality.