I'd like to have a flexible schema in Mongo, but would also like to enforce a schema for subsequent updates. Is it possible to store the validation in the document like the following?
I have tried this, but can't seem to convert the string into a Joi object.
{
"_id" : ObjectId("53d5dce1fc87899b2b3c2def"),
"name" : {
"validator" : "Joi.string().alphanum().min(3).max(30).required()",
"value" : "Bob"
},
"email" : {
"validator" : "Joi.string().email()",
"value" : "bob#gmail.com"
}
}
Most of the time, storing executable code in a database is not a good idea. What will you do when you realize a validator function which is already stored in a billion documents needs to be modified? What if someone manages to insert a document with validation code which does more malicious stuff than just validating?
I would really recommend you to determine the type of the document and the appropriate validation routine for each type in node.js.
But when you insist on having executable code for each document in the document itself, you can run that code in node.js using the vm.runInContext(object.validator, object) method. Keep in mind that this requires access to the whole document in node.js, so you can not do partial updates. Also keep in mind that, as I said, it might not be a very good idea.
In the upcoming Mongo 3.2 version they are going to add document validation (slides).
It will work in a different way and looking at your requirements it looks like it is possible to achieve what you want. It is possible to specify the type of the field, check the existence and pass through regex.
Here is a little bit about validation. You can specify validation rules for each collection, using validator option using almost all mongo query operators (except $geoNear, $near, $nearSphere, $text, and $where).
To create a new collection with a validator, use:
db.createCollection("your_coll", {
validator: { `your validation query` }
})
To add a validator to the existing collection, you can add the validator:
db.createCollection("your_coll", {
validator: { `your validation query` }
})
Validation work only on insert/update, so when you create a validator on your old collection, the previous data will not be validated (you can write application level validation for a previous data). You can also specify validationLevel and validationAction to tell what will happen if the document will not pass the validation.
If you try to insert/update the document with something that fails the validation, (and have not specified any strange validationLevel/action) then you will get an error on writeResult (sadly enough the error does not tell you what failed and you get only default validation failed):
WriteResult({
"nInserted" : 0,
"writeError" : {
"code" : 121,
"errmsg" : "Document failed validation"
}
})
Related
I have a Mongo collection that has two fields, let's say "name" and "randomString".
I want to create a random string for a name, only if it doesn't exist already. So the first request for { name: "SomeName" } will result in saving e.g. { name: "someName", randomString: "abc" }. The second request will do nothing.
Is there a mongo command for this? All I could find are things like findOneAndUpdate, replaceOne etc, who all support an optional "upsert" but their behavior on match is to update, I want the behavior on match to be do nothing.
I'm not looking for an if-then solution like in this question, as I have a race condition issue - I need to be able to get multiple requests simultaneously without updating the document or failing any of the requests.
Yes there is a command for this you can do this by using $addToSet method.
For more info please go through the given link: https://docs.mongodb.com/manual/reference/operator/update/addToSet/
PS: If you still have any confusion regarding this question please feel free to comment further.
Thanks
This is the solution I found in the end:
CustomerRandomString.findOneAndUpdate(
{ name: "someName" },
{
$setOnInsert: { randomString: generateRandomString() },
},
{ upsert: true },
);
The setOnInsert operator only applies when creating a new document, which is exactly what I needed.
EDIT: per the docs, this solution requires a unique index on the field in order to fully avoid duplicates.
You can easily do it using the $exists command to check for randomString field and then use $set in an aggregation pipeline to upsert that field.
db.collection.updateMany({"name":someName,"randomString":{$exists: false}},[{$set:{"randomString":"abcd"}}],{upsert:true})
If the condition query doesn't match with any documents, then it returns null.
Note: Aggregation pipeline works in updateMany() only from MongoDB version 4.2 and above.
So I have a String array field in MongoDB collection that I would like to add a String that is an ObjectId. It gets added but gets saved as an ObjectId instead of a String.
users_collection.update_one({
"_id": ObjectId(user['_id'])
}, {
"$push": {
"profile.surveys.completedInTimeSurveyIDs": "5dc71ee34283e125a9edc96b"
}
})
Which always saves in the collection document as:
But I want it to be:
Likely you have defined a schema in your framework and your framework know that the type of the value referred by your path (here profile.surveys.completedInTimeSurveyIDs.$ would have been specified as oid and thus your string is cast as so)
Alternatives are:
design your schema according to your spec (as a string)
bypass the framework and directly use the driver (if exceptional and possible)
consider really storing an ObjectId and adapt your code upon retrieval (str() if needed)
I would advise you to do the latter (if you were to aggregate stuff, lookup, even populate, or any other work involving your array element, you are likely to need an ObjectId)
TLDR
Is there a way to limit queryByExample to a collection in NodeJS?
Problem faced
I have a complex query with some optional fields (i.e. sometimes some search fields will be omitted). So I need to create a query dynamically, e.g. in JSON. QueryByExample seems to be the right tool to use here as it gives me that flexibility to pass a JSON. However my problem is that I would like to limit my search to only one collection or directory.
e.g. I was hoping for something like
searchJSON = {
title: { $word: "test" },
description: { $word: "desc" }
};
//query
db.documents.query(qb.where(
qb.collection("collectionName"),
qb.byExample(searchJSON)
)).result()...
In this case searchJSON could have been built dynamically, for example maybe sometimes title may be omitted from the search.
This doesn't work because the query builder only allows queryByExample to be the only query. But I'd instead like to built a dynamic search query which is limited to a collection or directory.
At present, I think you would have to express the query with QueryBuilder instead of Query By Example using
qb.and([
qb.collection('collectionName'),
qb.word('title', 'test'),
qb.word('description', 'desc')
])
See http://docs.marklogic.com/jsdoc/queryBuilder.html#word
That said, it should be possible for the Node.js API to relax that restriction based on the fixes in MarkLogic 9.0-2
Please file an issue on https://github.com/marklogic/node-client-api
I am using the Mongoose driver with NodeJS. I have quite a simple update call whose purpose is to sync an external source of meetings to my database:
collection.update({ meeting_id: doc.meeting_id}, newDoc, {upsert:true})
The object returned determines whether or not an update or an insert occurred. This works perfectly. My issue is that I must determine if an actual change occurred. When you update a document with itself, MongoDB treats this in exactly the same way as if all fields were changed.
So my question is: Is there any good way to tell if anything actually changed? I could search for each document then compare each field manually, but this seems like a poor (and slow) solution.
you can use findAndModify which will return updated results as compared to update which will return no of updated records.
collection.findAndModify(
{ meeting_id: doc.meeting_id},
newDoc,
{ new: true },
function (err, documents) {
res.send({ error: err, affected: documents });
}
);
I have a sample schema like this -
Comment.add({
text:String,
url:{type:String,unique:true},
username:String,
timestamp:{type:Date,default:Date}
});
Feed.add({
url:{type:String, unique:true },
username:String,
message:{type:String,required:'{PATH} is required!'},
comments:[Comment],
timestamp:{type:Date,default:Date}
});
Now, I don't want to expose the _id fields to the outside world that's why I am not sending it to the clients anywhere.
Now, I have two important properties in my comment schema (username,url)
What I want to do is update the content of the sub document that satisfies
feed.url
comment.url
comment.username
if the comment.username is same as my client value req.user.username then update the comment.text property of that record whose url was supplied by client in req.body.url variable.
One long and time consuming approach I thought is to first find the feed with the given url and then iterating over all the subdocuments to find the document which satisfies the comment.url==req.body.url and then check if the comment.username==req.user.username if so, update the comment object.
But, I think there must be an easier way of doing this?
I already tried -
db.feeds.update({"username":"harshitladdha93#gmail.com","comments.username":"harshitladdha3#gmail.com","comments.url":"test"},{$set:{"comments.$.text":"updated text 2"}})
found from http://www.tagwith.com/question_305575_how-to-find-and-update-subdocument-within-array-based-on-parent-property
but this updates even when the comments.url or comments.usernamematches other sub documents
and I also tried
db.feeds.distinct("comments._id",{"comments.url":req.body.url})
to find the _id of document associated with the url but it returns all the _id in the subdocument
First off - you should not rely on _id not being seen by the outside world in terms of security. This is a very bad idea for a multitude of reasons (primarily REST and also the fact that it's returned by default with all your queries).
Now, to address your question, what you want is the $elemMatch operator. This says that you're looking for something where the specified sub-document within an array matches multiple queries.
E.g.
db.feeds.update({
"username":"harshitladdha93#gmail.com",
comments: {
$elemMatch: {
username: "harshitladdha3#gmail.com",
url: "test"
}
}
}, {$set: {"comments.$.text":"updated text 2"}})
If you don't use $elemMatch you're saying that you're ok with the document if any of the comments match your query - i.e. if there is a comment by user "harshitladdha3#gmail.com", and separate comment has a url "test", the document will match unless you use $elemMatch