i have a person document, that have list of pets:
{
"personId": "kjadfh97r0",
"pets": [
{
"petId": "dfjkh32476",
"name": "kitty",
"kind": "cat"
},
{
"petId": "askdjfh2794857",
"name": "rexy",
"kind": "dog"
}
]
}
I want to find certain pen inside of certain person and update just some fields, so I did something like:
db.people.findAndModify({
query: { "personId": "kjadfh97r0", "pets.petId": "dfjkh32476" },
update: {"$set":{"pets.$":{"kind":"tiger"}}}
})
but what happens to me is that the whole document is replaced with "kind":"tiger", and I just wanted to update the "kind" field any keep the rest.
You should specify entire path for $set when you update nested document using positional operator, otherwise the document will be replaced:
db.people.findAndModify({
query: { "personId": "kjadfh97r0", "pets.petId": "dfjkh32476" },
update: { $set: {"pets.$.kind": "tiger"} }
})
Related
I have a collection in MongoDB containing search history of a user where each document is stored like:
"_id": "user1"
searchHistory: {
"product1": [
{
"timestamp": 1623482432,
"query": {
"query": "chocolate",
"qty": 2
}
},
{
"timestamp": 1623481234,
"query": {
"query": "lindor",
"qty": 4
}
},
],
"product2": [
{
"timestamp": 1623473622,
"query": {
"query": "table",
"qty": 1
}
},
{
"timestamp": 1623438232,
"query": {
"query": "ike",
"qty": 1
}
},
]
}
Here _id of document acts like a foreign key to the user document in another collection.
I have backend running on nodejs and this function is used to store a new search history in the record.
exports.updateUserSearchCount = function (userId, productId, searchDetails) {
let addToSetData = {}
let key = `searchHistory.${productId}`
addToSetData[key] = { "timestamp": new Date().getTime(), "query": searchDetails }
return client.db("mydb").collection("userSearchHistory").updateOne({ "_id": userId }, { "$addToSet": addToSetData }, { upsert: true }, async (err, res) => {
})
}
Now, I want to get search history of a user based on query only using the db.find().
I want something like this:
db.find({"_id": "user1", "searchHistory.somewildcard.query": "some query"})
I need a wildcard which will replace ".somewildcard." to search in all products searched.
I saw a suggestion that we should store document like:
"_id": "user1"
searchHistory: [
{
"key": "product1",
"value": [
{
"timestamp": 1623482432,
"query": {
"query": "chocolate",
"qty": 2
}
}
]
}
]
However if I store document like this, then adding search history to existing document becomes a tideous and confusing task.
What should I do?
It's always a bad idea to save values are keys, for this exact reason you're facing. It heavily limits querying that field, obviously the trade off is that it makes updates much easier.
I personally recommend you do not save these searches in nested form at all, this will cause you scaling issues quite quickly, assuming these fields are indexed you will start seeing performance issues when the arrays get's too large ( few hundred searches ).
So my personal recommendation is for you to save it in a new collection like so:
{
"user_id": "1",
"key": "product1",
"timestamp": 1623482432,
"query": {
"query": "chocolate",
"qty": 2
}
}
Now querying a specific user or a specific product or even a query substring is all very easily supported by creating some basic indexes. an "update" in this case would just be to insert a new document which is also much faster.
If you still prefer to keep the nested structure, then I recommend you do switch to the recommended structure you posted, as you mentioned updates will become slightly more tedious, but you can still do it quite easily using arrayFilters for updating a specific element or just using $push for adding a new search
I have a collection with a layout that looks something like this:
student1 = {
"First_Name": "John",
"Last_Name": "Doe",
"Courses": [
{
"Course_Id": 123,
"Course_Name": "Computer Science",
"Has_Chosen_Modules": false
},
{
"Course_Id": 284,
"Course_Name": "Mathematics",
"Has_Chosen_Modules": false
}
]
};
I also have the following update query:
db.Collection_Student.update(
{
$and: [
{First_Name: "John"},
{Last_Name: "Doe"}
]
},
{
$set : { "Courses.0.Has_Chosen_Modules" : true }
}
);
This code will currently update the Computer Science Has_Chosen_Modules value to true since the index is hardcoded. However, what if I wanted to update the value of Has_Chosen_Modules via the Course_Id instead (as the course might not necessarily be at the same index every time)? How would I achieve this without it affecting the other courses that a given student is taking?
You can select any item in the sub array of your document by targeting any property in the sub array of your document by using dot .
You can easily achieve this by the following query.
db.Collection_Student.update(
{
First_Name: "John",
Last_Name: "Doe",
'Courses.Course_Id': 123
},
{
$set : { "Courses.$.Has_Chosen_Modules" : true }
}
);
Conditions in search filter are by default treated as $and operator, so you don't need to specifically write $and for this simple query.
I’ve been trying to update the data in my mongoDB.
I want to update all products with a new productName field.
my data looks something like:
{
"id": "12345",
"products": [{
"id": 0
"productCode": "test",
"status": "PENDING",
},
{
"id": 1
"productCode": "test",
"status": "COMPLETE",
}],
}
When I try the following. I get this error The positional operator did not find the match needed from the query.
db.customers.updateMany(
{ id: "12345" },
{ $set: {
"products.$.productName": "Name here" }
}
)
If I do account.0.productName then it’s fine and updates. I’m not sure why $ is not working for me
db.customers.updateMany(
{ id: "12345" },
{ $set: {
"products.0.productName": "Name here" }
}
)
Positional operator is not working because you are not using the array into the find (first object)
If you try this query it will work as expected because you have the position finding by products.id.
Otherwise, if you don't have the position into array where update, yo can't use $ operator in this way. You need this query:
db.collection.update({
"id": "12345",
},
{
"$set": {
"products.$[].newField": "test2"
}
},
{
"multi": true
})
Mongo playground example here
Using $[] you can reference the array and add the value into each object.
$[] docs here
It says:
The all positional operator $[] indicates that the update operator should modify all elements in the specified array field.
That's exactly we want :)
I have this object and I'd like to update the name field "field" of all the document in the collections. I read the mongodb documentation and it says $rename doesn't work in this case. I should execute a forEach but I don't know how which command use
{
"name": "foo"
"array": [
"object": {
"field": "name"
}
]
}
Do it manually:
db.collection.find().forEach(function(doc) {
if (doc.array) {
doc.array.forEach(function(edoc) {
if (edoc.object) {
doc.object.new_field = edoc.object.field
delete edoc.object.field
}
})
db.test.update({ "_id" : doc._id }, doc)
}
})
This should get you started. It handles missing or empty array arrays, but not an array value of the wrong type, or an object value of the wrong type.
$rename modifier for update Ops should work (http://docs.mongodb.org/manual/reference/operator/update/rename/)
Imagine a collection like yours:
{
"name": "foo",
"array":[
{"field": "name" }
]
}
You will be able to do something like this:
db.rename.update({},{$rename:{"name":"newName"}});
And the document will be as follows:
{
"newName": "foo",
"array":[
{"field": "name" }
]
}
In order to update all the collection you should use the multi option as follows:
db.rename.update({},{$rename:{"name":"newName"}}, {multi:true})
Regards
Here below is a hypothetical Users collection where more than one address is allowed:
{
"firstName": "Joe",
"lastName": "Grey",
...
"addresses":
[
{
"name": "Default",
"street": "..."
...
},
{
"name": "Home",
"street": "..."
...
},
{
"name": "Office",
"street": "..."
...
}
]
}
Every address has a name... which should be unique – e.g. there couldn't be two addresses named Default. If I want to update let's say the address at index 1 (Home), how do I ensure the update data does not contain names Default and Office?
I guess a two-steps approach (i.e. find and then update) wouldn't be very correct since data might be updated between the find and the subsequent update operation, isn't?
var renamed = 'Office'; // from user input
var users = getUserMongoCollection();
users.update({_id:userId, 'addresses.name': { $ne : renamed } },
{ $set : { 'addresses.1.name' : renamed } }, function(err){
//all done!
});
Find the record by ID, and only update it if the array doesn't contain the new name.