I was looking to pull(remove) values from my data collection based on array index.
this is how my collection looks.
"experience" : [
"neeee",
"avvvvvvv",
],
I'm looking to remove experience[1]
var update = {
$pull: {
'profile.experience': delet
}
};
this.findByIdAndUpdate(id,update,{ 'new': true},function(err,doc) {
if (err) { console.log(err);
callback(err);
} else if(doc){
callback(null,doc);
}
my delet looks like this: [1]
i was not able to delete (pull) what may be the reason.
Related
I am working with applications using MongoDB, nodeJs. I have a document with 2 level nested data on it. I want to push data of a 2-level nested array based on a 1-level "uuid". I will attach my document picture and you will know exactly what I wanted.
Node code:
await collection.update(
{
uuid: req.query.sub_uuid
},
{
$push: { subtests.uuid: req.body }
});
await test.save();
Thanks in Advance.
You have to use $arrayFilters that you can put some constraint on your update element inside the array.
db.collections.updateMany({
"subtests.uuid": 'your_uuid'
},
{
$set: {
{ $push: { "subtests.$[el].subtrests": { /*item you want to push in the array */ } } }
}
},
{
arrayFilters: [
{
"el.uuid": 'your_uuid'
}
]
})
with this approach, you can update only the element who have your uuid.
I need to push a new document into an array and use his _id.
Right now im using findOneAndUpdate, i know i can use { new: true } but i only need the created document and not the parent document.
this is my code so far
User.findOneAndUpdate(
{
'posts._id': req.params.id
},
{
$push: {
'posts.$.comments': {
from: {
_id: req.user._id,
username: req.user.username,
},
body: req.body.commentBody
}
}
},
err => {
if (err) console.log(err)
// Do something with ObjectId
}
);
Thanks in advance.
findOneAndUpdate callback gives you the updated document.
You have the Post's _id. You can use that to find the post to which you are adding the comment to. As you are pushing the comment, it will be the last element in the post array.
var mypost = doc.posts.find(function(post){
return post._id.toString()==req.params.id
});
console.log(mypost.comments[mypost.comments.length]._id)
I am reading all documents of a specific schema from Mongoose. Now in my program I am doing some modifications to the results I got from Mongoose over time. Something like this:
var model = mongoose.model("Doc", docSchema);
model.find(function(err, result){
// for each result do some modifications
});
How can I send all the results back to the database to be saved? Currently I am iterating the documents and doing a save() on every document. I think there must be a better way. But currently I only find information on updating documents IN the database without returning them. Or bulk updates which do the SAME to update to each document.
You can use update query with multi:true which update all documents in your db.
please find below reference code,
model.update({ "_id": id }, { $set: { "Key": "Value" } }, { multi: true }, function (err, records) {
if (err || !records) {
return res.json({ status: 500, message: "Unable to update documents." });
} else {
return res.json({ status: 200, message: "success" });
}
});
If you are trying to make the same change to each document in the results, you could do something like this:
model.update({ _id: { $in: results.map(doc=>doc._id) }}, { yourField: 'new value' }, { multi: true })
My document contains an array like:
{
"differentialDiagnosis" : "IART/Flutter",
"explanation" : "The rhythm.",
"fileName" : "A115a JPEG.jpg",
"history" : "1 year old with fussiness",
"interpretationList" : [
{
"interpretations" : [
ObjectId("54efe7c8d6d5ca3d5c580a22"),
ObjectId("54efe80bd6d5ca3d5c580a26")
]
},
{
"interpretations" : [
ObjectId("54efe80bd6d5ca3d5c580a26"),
ObjectId("54efe82ad6d5ca3d5c580a28")
]
}
],
}
and I want to remove all occurrences of ObjectId("54efe80bd6d5ca3d5c580a26"),
but I write a query:
db.ekgs.update({'interpretationList.interpretations':ObjectId("54c09fb3581c4c8c218d1a40")}, {$pull:{ 'interpretationList.$.interpretations':{ ObjectId("54c09fb3581c4c8c218d1a40")}})
This removes only first occurrence of ObjectId("54efe80bd6d5ca3d5c580a26").
The reason your query is only removing the first occurrence is because, as explained in this page in the documentation, "the positional $ operator acts as a placeholder for the first element that matches the query document".
The problem is that it is really tricky to deal with these types of updates with schema having embedded arrays in embedded objects in embedded arrays. In order to get around this problem, if you are able to flatten the schema, then your update becomes much easier. So if instead, your document looked like this:
{
"differentialDiagnosis" : "IART/Flutter",
"explanation" : "The rhythm.",
"fileName" : "A115a JPEG.jpg",
"history" : "1 year old with fussiness",
"interpretations" : [
ObjectId("54efe7c8d6d5ca3d5c580a22"),
ObjectId("54efe80bd6d5ca3d5c580a26"),
ObjectId("54efe82ad6d5ca3d5c580a28")
]
}
Then your query would be as simple as the one below. (Remember to add { "multi": true } as an option if you want to update multiple documents).
db.ekgs.update(
{ "interpretations": ObjectId("54efe80bd6d5ca3d5c580a26")},
{ "$pull": { "interpretations": ObjectId("54efe80bd6d5ca3d5c580a26") }}
);
But I understand that you might not be able to change the schema. In that case, you can try a solution that requires a small script. In the mongo shell, you can use the following bit of JavaScript to do the operation.
// Get cursor with documents requiring updating.
var oid = ObjectId("54efe80bd6d5ca3d5c580a26");
var c = db.ekgs.find({ "interpretationList.interpretations": oid });
// Iterate through cursor, removing oid from each subdocument in interpretationList.
while (c.hasNext()) {
var isModified = false;
var doc = c.next();
var il = doc.interpretationList;
for (var i in il) {
var j = il[i].interpretations.length;
while (j--) {
// If oid to remove is present, remove it from array
// and set flag that the document has been modified.
if (il[i].interpretations[j].str === oid.str) {
il[i].interpretations.splice(j, 1);
isModified = true;
}
}
}
// If modified, update interpretationList for document.
if (isModified) {
db.ekgs.update({ "_id": doc._id }, { "$set": { "interpretationList": il }});
}
}
UPDATE: Example of how it might work using the Node.js driver.
// Get cursor with documents requiring updating.
var oid = new ObjectID("54efe80bd6d5ca3d5c580a26");
var ekgs = db.collection("ekgs");
ekgs.find({ "interpretationList.interpretations": oid },
function(err, c) {
if(err) throw err;
// Iterate through cursor, removing oid from each subdocument in interpretationList.
c.each(function(err, doc) {
if (err) throw err;
// If doc is null then the cursor is exhausted/empty and closed.
if (doc != null) {
var isModified = false;
var il = doc.interpretationList;
for (var i in il) {
var j = il[i].interpretations.length;
while (j--) {
// If oid to remove is present, remove it from array
// and set flag that the document has been modified.
if (il[i].interpretations[j].equals(oid)) {
il[i].interpretations.splice(j, 1);
isModified = true;
}
}
}
// If modified, update interpretationList for document.
if (isModified) {
ekgs.update({ "_id": doc._id },
{ "$set": { "interpretationList": il }},
function(err, res) {
if (err) throw err;
// Callback.
console.log(res);
});
}
}
});
});
Assuming I have a collection in MongoDB with 5000 records, each containing something similar to:
{
"occupation":"Doctor",
"name": {
"first":"Jimmy",
"additional":"Smith"
}
Is there an easy way to rename the field "additional" to "last" in all documents? I saw the $rename operator in the documentation but I'm not really clear on how to specify a subfield.
You can use:
db.foo.update({}, {
$rename: {
"name.additional": "name.last"
}
}, false, true);
Or to just update the docs which contain the property:
db.foo.update({
"name.additional": {
$exists: true
}
}, {
$rename: {
"name.additional": "name.last"
}
}, false, true);
The false, true in the method above are: { upsert:false, multi:true }. You need the multi:true to update all your records.
Or you can use the former way:
remap = function (x) {
if (x.additional) {
db.foo.update({
_id: x._id
}, {
$set: {
"name.last": x.name.additional
}, $unset: {
"name.additional": 1
}
});
}
}
db.foo.find().forEach(remap);
In MongoDB 3.2 you can also use
db.students.updateMany({}, {
$rename: {
"oldname": "newname"
}
})
The general syntax of this is
db.collection.updateMany(filter, update, options)
https://docs.mongodb.com/manual/reference/method/db.collection.updateMany/
You can use the $rename field update operator:
db.collection.update(
{},
{ $rename: { 'name.additional': 'name.last' } },
{ multi: true }
)
If ever you need to do the same thing with mongoid:
Model.all.rename(:old_field, :new_field)
UPDATE
There is change in the syntax in monogoid 4.0.0:
Model.all.rename(old_field: :new_field)
Anyone could potentially use this command to rename a field from the collection (By not using any _id):
dbName.collectionName.update({}, {$rename:{"oldFieldName":"newFieldName"}}, false, true);
see FYI
I am using ,Mongo 3.4.0
The $rename operator updates the name of a field and has the following form:
{$rename: { <field1>: <newName1>, <field2>: <newName2>, ... } }
for e.g
db.getCollection('user').update( { _id: 1 }, { $rename: { 'fname': 'FirstName', 'lname': 'LastName' } } )
The new field name must differ from the existing field name. To specify a in an embedded document, use dot notation.
This operation renames the field nmae to name for all documents in the collection:
db.getCollection('user').updateMany( {}, { $rename: { "add": "Address" } } )
db.getCollection('user').update({}, {$rename:{"name.first":"name.FirstName"}}, false, true);
In the method above false, true are: { upsert:false, multi:true }.To update all your records, You need the multi:true.
Rename a Field in an Embedded Document
db.getCollection('user').update( { _id: 1 }, { $rename: { "name.first": "name.fname" } } )
use link : https://docs.mongodb.com/manual/reference/operator/update/rename/
This nodejs code just do that , as #Felix Yan mentioned former way seems to work just fine , i had some issues with other snipets hope this helps.
This will rename column "oldColumnName" to be "newColumnName" of table "documents"
var MongoClient = require('mongodb').MongoClient
, assert = require('assert');
// Connection URL
//var url = 'mongodb://localhost:27017/myproject';
var url = 'mongodb://myuser:mypwd#myserver.cloud.com:portNumber/databasename';
// Use connect method to connect to the server
MongoClient.connect(url, function(err, db) {
assert.equal(null, err);
console.log("Connected successfully to server");
renameDBColumn(db, function() {
db.close();
});
});
//
// This function should be used for renaming a field for all documents
//
var renameDBColumn = function(db, callback) {
// Get the documents collection
console.log("renaming database column of table documents");
//use the former way:
remap = function (x) {
if (x.oldColumnName){
db.collection('documents').update({_id:x._id}, {$set:{"newColumnName":x.oldColumnName}, $unset:{"oldColumnName":1}});
}
}
db.collection('documents').find().forEach(remap);
console.log("db table documents remap successfully!");
}
If you are using MongoMapper, this works:
Access.collection.update( {}, { '$rename' => { 'location' => 'location_info' } }, :multi => true )