I'm new to MongoDB and have to work on a legacy project that I didn't create... and I'm struggling!
I need to reset some documents in one of my collections, based on a particular field value. I have had some success with this so far, but some of the data I need to update is within nested arrays in that document, and I can't work that part out.
Below is an example of one document in the collection:
{
"_id" : ObjectId("1234567890"),
"currentStatus" : "approved",
"itemsInstalled" : [
{
"installDate" : ISODate("2017-04-18T00:00:00.000Z"),
"_id" : ObjectId("1234567890"),
"status" : "approved"
},
{
"installDate" : ISODate("2017-04-18T00:00:00.000Z"),
"_id" : ObjectId("0987654321"),
"status" : "approved"
}
],
"__v" : 5005,
"approvalDate" : ISODate("2017-12-04T10:40:01.580Z"),
"approvedBy" : "automatic"
}
I need to update every document in my collection where the approvedBy field is set to automatic, and leave the others untouched.
For the documents I am updating, I need to remove the approvalDate and approvedBy fields completely, change the currentStatus field to action and change every item in the itemsInstalled array to pending. Everything else can stay as it is.
This is something I would persist with solving myself if I had more time.
Unfortunately, to my knowledge, you can't update multiple array elements. Your best bet is probably to use forEach. You can accomplish what you want with something like this:
db.your_collection.find({
approvedBy: "automatic"
}).forEach(function(doc) {
for(var i = 0; i < doc.itemsInstalled.length; i++) {
doc.itemsInstalled[i].status = "pending";
}
doc.currentStatus = "action";
delete doc.approvedBy;
delete doc.approvalDate;
db.your_collection.update({_id: doc._id}, doc);
});
Using forEach, you can update all of the array elements at once. The downside is that you will be performing multiple update queries, so you should be careful about doing this on particularly large collections or as part of your application logic. Ideally this should be a one-time use scenario.
Related
I would like to preface this with saying that english is not my mother tongue, if any of my explanations are vague or don't make sense, please let me know and I will attempt to make them clearer.
I have a document containing some nested data. Currently product and customer are arrays, I would prefer to have them as straight up ObjectIDs.
{
"_id" : ObjectId("5bab713622c97440f287f2bf"),
"created_at" : ISODate("2018-09-26T13:44:54.431Z"),
"prod_line" : ObjectId("5b878e4c22c9745f1090de66"),
"entries" : [
{
"order_number" : "123",
"product" : [
ObjectId("5ba8a0e822c974290b2ea18d")
],
"customer" : [
ObjectId("5b86a20922c9745f1a6408d4")
],
"quantity" : "14"
},
{
"order_number" : "456",
"product" : [
ObjectId("5b878ed322c9745f1090de6c")
],
"customer" : [
ObjectId("5b86a20922c9745f1a6408d5")
],
"quantity" : "12"
}
]
}
I tried using the following query to update it, however that proved unsuccessful as Mongo didn't behave quite as I had expected.
db.Document.find().forEach(function(doc){
doc.entries.forEach(function(entry){
var entry_id = entry.product[0]
db.Document.update({_id: doc._id}, {$set:{'product': entry_id}});
print(entry_id)
})
})
With this query it sets product in the root of the object, not quite what I had hoped for. What I was hoping to do was to iterate through entries and change each individual product and customer to be only their ObjectId and not an array. Is it possible to do this via the mongo shell or do I have to look for another way to accomplish this? Thanks!
In order to accomplish your specified behavior, you just need to modify your query structure a bit. Take a look here for the specific MongoDB documentation on how to accomplish this. I will also propose an update to your code below:
db.Document.find().forEach(function(doc) {
doc.entries.forEach(function(entry, index) {
var productElementKey = 'entries.' + index + '.product';
var productSetObject = {};
productSetObject[productElementKey] = entry.product[0];
db.Document.update({_id: doc._id}, {$set: productSetObject});
print(entry_id)
})
})
The problem that you were having is that you were not updating the specific element within the entries array, but rather adding a new key to the top-level of the document named product. Generally, in order to set the value of an inner document within an array, you need to specify the array key first (entries in this case) and the inner document key second (product in this case). Since you are trying to set specific elements within the entries array, you need to also specify the index in your query object, I have specified above.
In order to update the customer key in the inner documents, simply switch out the product for customer in my above code.
You're trying to add a property 'product' directly into your document with this line
db.Document.update({_id: doc._id}, {$set:{'product': entry_id}});
Try to modify all your entries first, then update your document with this new array of entries.
db.Document.find().forEach(function(doc){
let updatedEntries = [];
doc.entries.forEach(function(entry){
let newEntry = {};
newEntry["order_number"] = entry.order_number;
newEntry["product"] = entry.product[0];
newEntry["customer"] = entry.customer[0];
newEntry["quantity"] = entry.quantity;
updatedEntries.push(newEntry);
})
db.Document.update({_id: doc._id}, {$set:{'entries': updatedEntries}});
})
You'll need to enumerate all the documents and then update the documents one and a time with the value store in the first item of the array for product and customer from each entry:
db.documents.find().snapshot().forEach(function (elem) {
elem.entries.forEach(function(entry){
db.documents.update({
_id: elem._id,
"entries.order_number": entry.order_number
}, {
$set: {
"entries.$.product" : entry.product[0],
"entries.$.customer" : entry.customer[0]
}
}
);
});
});
Instead of doing 2 updates each time you could possibly use the filtered positional operator to do all updates to all arrays items within one update query.
I have created a collection and added just a name field and tried to apply the following index.
db.names.createIndex({"name":1})
Even after applying the index I see the below result.
db.names.find()
{ "_id" : ObjectId("57d14139eceab001a19f7e82"), "name" : "kkkk" } {
"_id" : ObjectId("57d1413feceab001a19f7e83"), "name" : "aaaa" } {
"_id" : ObjectId("57d14144eceab001a19f7e84"), "name" : "zzzz" } {
"_id" : ObjectId("57d14148eceab001a19f7e85"), "name" : "dddd" } {
"_id" : ObjectId("57d1414ceceab001a19f7e86"), "name" : "rrrrr" }
What am I missing here.
Khans...
the way you built your index is correct however building an ascending index on names wont return the results in ascending order.
if you need results to be ordered by name you have to use
{db.names.find().sort({names:1})}
what happens when you build an index is that when you search for data the Mongo process perform the search behind the scenes in an ordered fashion for faster outcomes.
Please note: if you just want to see output in sorted order. you dont even need an index.
You won't be able to see if an index has been successfully created (unless there is a considerable speed performance) by running a find() command.
Instead, use db.names.getIndexes() to see if the index has been created (it may take some time if you're running the index in the background for it to appear in the index list)
I have a document something like this :
myDoc : {
_id : a101
name : John,
batch : [{
_id : batch101,
value : physics
},{
_id : batch102,
value : chemistry
},{
_id : batch103,
value : maths
}]
}
I want to update the "value" to "computers" where the batch._id is either "batch101" or "batch102" (not batch103).
Please help! Thanks in advance.
-Manish :)
As noted in comments on the orignal question, the best solution here might be to work with the document on the client side. I will break this down into a few steps:
1) Query for the document. You mentioned you are working in node, so this will be represented in JSON. Lets call this variable x
2) Go through your document finding the elements you want to update, this might look like:
for(i = 0; i < x.batch.length; i++) {
if(x.batch[i]._id == 'batch101') {
//do something
}
}
(this code is not complete, obviously, but gives you an idea of what you want)
3) Now, using this changed document, update the old document in mongoDB.
This process should allow you to achieve your goal of updating certain elements in the batch list.
I need help incrementing value of all keys in participants without having to know name of the keys inside of it.
> db.conversations.findOne()
{
"_id" : ObjectId("4faf74b238ba278704000000"),
"participants" : {
"4f81eab338ba27c011000001" : NumberLong(2),
"4f78497938ba27bf11000002" : NumberLong(2)
}
}
I've tried with something like
$mongodb->conversations->update(array('_id' => new \MongoId($objectId)), array('$inc' => array('participants' => 1)));
to no avail...
You need to redesign your schema. It is never a good idea to have "random key names". Even though MongoDB is schemaless, it still means you need to have defined key names. You should change your schema to:
{
"_id" : ObjectId("4faf74b238ba278704000000"),
"participants" : [
{ _id: "4f81eab338ba27c011000001", count: NumberLong(2) },
{ _id: "4f78497938ba27bf11000002", count: NumberLong(2) }
]
}
Sadly, even with that, you can't update all embedded counts in one command. There is currently an open feature request for that: https://jira.mongodb.org/browse/SERVER-1243
In order to still update everything, you should:
query the document
update all the counts on the client side
store the document again
In order to prevent race conditions with that, have a look at "Compare and Swap" and following paragraphs.
It is not possible to update all nested elements in one single move in current version of MongoDB. So I can advice to use "foreach {}".
Read realted topic: How to Update Multiple Array Elements in mongodb
I hope this feature will be implemented in next version.
I have the following collection:
{
"Milestones" : [
{ "ActualDate" : null,
"Index": 0,
"Name" : "milestone1",
"TargetDate" : ISODate("2011-12-13T22:00:00Z"),
"_id" : ObjectId("4ee89ae7e60fc615c42e28d1")},
{ "ActualDate" : null,
"Index" : 0,
"Name" : "milestone2",
"TargetDate" : ISODate("2011-12-13T22:00:00Z"),
"_id" : ObjectId("4ee89ae7e60fc615c42e28d2") } ]
,
"Name" : "a", "_id" : ObjectId("4ee89ae7e60fc615c42e28ce")
}
I want to update definite documents: that have specified _id, List of Milestones._id and ActualDate is null.
I dotnet my code looks like:
var query = Query.And(new[] { Query.EQ("_id", ObjectId.Parse(projectId)),
Query.In("Milestones._id", new BsonArray(values.Select(ObjectId.Parse))),
Query.EQ("Milestones.ActualDate", BsonNull.Value) });
var update = Update.Set("Milestones.$.ActualDate", DateTime.Now.Date);
Coll.Update(query, update, UpdateFlags.Multi, SafeMode.True);
Or in native code:
db.Projects.update({ "_id" : ObjectId("4ee89ae7e60fc615c42e28ce"), "Milestones._id" : { "$in" : [ObjectId("4ee89ae7e60fc615c42e28d1"), ObjectId("4ee89ae7e60fc615c42e28d2"), ObjectId("4ee8a648e60fc615c41d481e")] }, "Milestones.ActualDate" : null },{ "$set" : { "Milestones.$.ActualDate" : ISODate("2011-12-13T22:00:00Z") } }, false, true)
But only the first item is being updated.
This is not possible in current moment. Flag multi in update means update of multiple root documents. Positional operator can match only one nested array item. There is such feature in mongodb jira. You can vote up and wait.
Current solution can be only load document, update as you wish and save back or multiple atomic update for each nested array id.
From documentation at mongodb.org:
Currently the $ operator only applies to the first matched item in the
query
As answered by Andrew Orsich, this is not possible for the moment, at least not as you wish. But loading the document, modifying the array then saving it back will work. The risk is that some other process could modify the array in the meantime, so you would overwrite its changes. To avoid this, you can use optimistic locking, especially if the array is not modified every second.
load the document, including a new attribute: milestones_version
modify the array as needed
save back to mongodb, but now add a query constraint on the milestones_version, and increment it:
db.Projects.findAndModify({
query: {
_id: your_project_id,
milestones_version: expected_milestones_version
},
update: {
$set: {
Milestones: modified_milestones
},
$inc: {
milestones_version: 1
}
},
new: 1
})
If another process modified the milestones array (and hence the milestones_version) before we did, then this command will do nothing and simply return null. We just need to reload the document and try again. If the array is not modified every second, then this will be very rare and will not have any impact on performance.
The main problem with this solution is that you have to edit every Project, one by one (no multi: true). You could still write a javascript function and have it run on the server though.
According to their JIRA page "This new feature is available starting with the MongoDB 3.5.12 development version, and included in the MongoDB 3.6 production version"
https://jira.mongodb.org/browse/SERVER-1243