My aplication has this structure:
Project (model)
-> tracks (collection)
-> track (model)
-> clips (collection)
clip (model)
I need to fetch only parent project model. It will cause change of all data structure. I get JSON
{ "_id" : "123",
"name" : "name",
"tracks" : [ { "clips" : [ { "audioName" : "audio name",
"audioPath" : "audio/path.wav",
"duration" : 123,
"id" : "track0-1"
} ],
"mute" : false,
"name" : "track0",
"selected" : false,
"volume" : 100
},
{ "clips" : [ ],
"mute" : false,
"name" : "track1",
"selected" : false,
"volume" : 100
}
]
}
I have parse method:
parse: function (data) {
this.get('tracks').reset(data.tracks);
delete data.tracks;
return data;
}
I am not able to parse clips. In model track, attribute clips has behavior like javascript array instead of backbone model.
How can I parse clips?
parse is only used to parse responses from the server. So you won't be able to use it to create your clips collection.
So you may want to change the way you do that (maybe have a look at Backbone-relational, I think it deals with this kind of stuff). Here's a possible solution (to be put in your model):
initialize: function() {
this.listenTo(this, 'change:clips', this.onChangeClips);
// the rest of your stuff
},
onChangeClips: function() {
var clips = this.get('clips');
if(Object.prototype.toString.call(clips) === '[object Array]')
this.set('clips', new Clips(clips), {silent: true});
}
Source to test if array: Check if object is array?
Note: this will remove any reference to an existing collection (which you seem to have), so you may want to keep a reference to your collection in your model (like in a _clips attribute) to reset it with the new clips array.
Related
I am connecting to the Yelp API using the RapidAPI module in Nodejs. I am able to request a token, connect, and request data, retrieve that data, and insert the relevant information for each result it into mongodb. Here's where it gets complicated...
Let's say I make a Yelp API request and search for bars. I get a list of bars and insert them into the database. Let's say one of these in the list is "Joe's Bar & Grill". One of the fields in my mongodb is "type" and it's an array. So now, this particular document will look something like this:
{
id: 'joes-bar-and-grill',
name: 'Joe\'s Bar & Grill',
type: ['bar']
}
But then I run another request on the Yelp API on "restaurants", and in this list "Joe's Bar & Grill" shows up again. Instead of inserting a new duplicate document into mongodb, I'd like the existing document to end up looking like this:
{
id: 'joes-bar-and-grill',
name: 'Joe\'s Bar & Grill',
type: ['bar', 'restaurant']
}
In addition to this, let's say I run another request again for "bars", and "Joe's Bar & Grill" comes up again. I don't want it to automatically insert "bar" into the type array again, if "bar" already exists in its array.
I've tried findOneAndUpdate with upsert: true and a $push of new data into the array, but I cannot get it to work at all. Does anyone have any ideas?
You can use findOneAndUpdate, combined with $addToSet (to make sure that an entry in the array only exists once) and $each (to allow passing arrays to $addToSet):
Bar.findOneAndUpdate({ id : 'joes-bar-and-grill' }, {
id : 'joes-bar-and-grill',
name : 'Joe\'s Bar & Grill',
$addToSet : { type : { $each : [ 'restaurant' ] } }
}, { upsert : true })
EDIT: now that you posted your entire code, the problem becomes more obvious.
For one, I'm not sure if the third and fourth arguments that you're passing to Location.update() make sense. As far as I know, the third should be an option object, and the fourth an async function.
Secondly, it looks like you're just ignoring any update errors.
And lastly, this isn't going to work:
for (var i = 0; i < payload.businesses.length; i++) { Location.update(...) }
Because Location.update() is asynchronous, the i variable will get clobbered (you should browse around on SO to find the explanation for that; for example, see this question).
You're going to need a library that will provide you with better async support, and preferably one that will also help limiting the number of update queries.
Once such library is async, and using it, your code would become something like this:
const async = require('async');
...
async.eachLimit(payload.businesses, 5, function(business, callback) {
Location.update({ yelpID : business.id }, {
name : business.name,
latitude : business.location.latitude,
longitude : business.location.longitude,
address1 : business.location.address1,
address2 : business.location.address2,
address3 : business.location.address3,
city : business.location.city,
state : business.location.state,
zip_code : business.location.zip_code,
country : business.location.country,
timezone : 'CST'
$addToSet : { type : 'bar' }
}, { upsert : true }, callback);
}, function(err) {
if (err) {
console.error(err);
} else {
console.log('All documents inserted');
}
});
You may use $addToSet operator
The $addToSet operator adds a value to an array unless the value is
already present, in which case $addToSet does nothing to that array.
$addToSet only ensures that there are no duplicate items added to the
set and does not affect existing duplicate elements. $addToSet does
not guarantee a particular ordering of elements in the modified set.
If the field is absent in the document to update, $addToSet creates
the array field with the specified value as its element.
If the field is not an array, the operation will fail.
The below solution assumes that on each update, you receive a single type and not an array. If the input document is an array itself, you may use robertklep's solution with $each operator
db.mycoll.update(
{ "id" : "joes-bar-and-grill" },
{
$set:{
name : 'Joe\'s Bar & Grill',
},
$addToSet : { type : 'restaurant' }
},
true, false);
I have also used $set operator.
The $set operator replaces the value of a field with the specified
value.
The $set operator expression has the following form:
{ $set: { field1: value1, ... } }
Here is the mongo shell output to explain it further :
> db.mycoll.find({ "id" : "joes-bar-and-grill" });
// NO RESULT
> db.mycoll.update(
... { "id" : "joes-bar-and-grill" },
... {
... $set:{
... name : 'Joe\'s Bar & Grill',
... },
... $addToSet : { type : 'restaurant' }
... },
... true, false);
WriteResult({
"nMatched" : 0,
"nUpserted" : 1,
"nModified" : 0,
"_id" : ObjectId("58e719b4d543c5e30d615d59")
})
// INSERTED A NEW DOCUMENT AS IT DOES NOT EXIST
> db.mycoll.find({ "id" : "joes-bar-and-grill" }); // FINDING THE OBJECT
{ "_id" : ObjectId("58e719b4d543c5e30d615d59"), "id" : "joes-bar-and-grill", "name" : "Joe's Bar & Grill", "type" : [ "restaurant" ] }
> db.mycoll.update(
... { "id" : "joes-bar-and-grill" },
... {
... $set:{
... name : 'Joe\'s Bar & Grill',
... },
... $addToSet : { type : 'bar' }
... },
... true, false);
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
// UPDATING THE DOCUMENT WITH NEW TYPE : "bar"
> db.mycoll.findOne({ "id" : "joes-bar-and-grill" });
{
"_id" : ObjectId("58e719b4d543c5e30d615d59"),
"id" : "joes-bar-and-grill",
"name" : "Joe's Bar & Grill",
"type" : [
"restaurant",
"bar"
]
}
I'm using mongify to migrate a mysql database into mongodb.
Doing that, 2 questions appeared:
1- How can i declare my translation file in order to have a embedded array of ids that references to the objects (that are stored in a different collection and can be retrieved through populate), instead of just embedding as json objects.
2- Embedded objects can have an unique id as objects in colections do?. On other projects i've used that approach to query for embedded objects, but if that id is not present i should use a different field.
Unfortunately the first request isn't possible with Mongify at the moment, it requires a custom script to do that.
I could give you more details if you want to send me your translation file (Make sure to remove any sensitive data).
As for number two, the embedded object will get a unique ID. You don't need to do anything special.
Hope that answers your questions.
from mongify isn't possible but in mongodb you can transform data as follows:
//find posts has array of objects
db.getCollection('posts').find({'_tags.0': {$exists: true}}).forEach( function (post) {
var items = [];
var property = '_tags';
post[property].forEach(function(element){
if(element._id !== undefined){
items.push(element._id);
}
});
if(items.length>0){
post[property] = items;
db.posts.update({_id:post._id},post);
}
});
Source Document:
{
"_id" : ObjectId("576aa0389863482f64051c81"),
"id_post" : 130155,
"_tags" : [
{
"_id" : ObjectId("576a9efd9863482f64000044")
},
{
"_id" : ObjectId("576a9efd9863482f6400004b")
},
{
"_id" : ObjectId("576a9efd9863482f64000052")
},
{
"_id" : ObjectId("576a9efd9863482f6400005a")
}
]
}
Final Document:
{
"_id" : ObjectId("576aa0389863482f64051c81"),
"id_post" : 130155,
"_tags" : [
ObjectId("576a9efd9863482f64000044"),
ObjectId("576a9efd9863482f6400004b"),
ObjectId("576a9efd9863482f64000052"),
ObjectId("576a9efd9863482f6400005a")
]
}
Using Mongoose, I have a model Page with an embedded model of Feeds. When i go to /pages, the page.title shows up for each page, but feeds data does not. how should i modify this code to properly display the data from the feeds array? thanks a million
db.pages exmaple:
{ "title" : "testing feeds", "_id" : ObjectId("123456"), "feeds" : [
{ "0" : { "name" : "twitter", "key" : "1234" },
"1" : { "name" : "flickr", "key" : "5678" },
}] }
web.js
app.get('/pages.:format?', function(req, res) {
Page.find({}, function(err, pages) {
switch (req.params.format) {
case 'json':
res.send(pages.map(function(d) {
return d.toObject();
}));
break;
default:
res.render('pages/index.jade', {
locals: {
title: 'ClrTouch | Pages',
pages: pages,
feeds: pages.feed,
}
});
}
});
});
view
- each page in pages
div.page
div.pagetitle= page.title
ul
- each feed in page.feeds
li.pagefeedname= feed.name
li.pagefeedkey= feed.key
with what i have, a list is generated in the view but the list items are empty. Thanks.
Is the model that you have here what you are also testing with? If so, then the reason your list is generated but nothing is displayed is because you do not currently have values in either.
li.pagefeedname=feed.name = "0" : { "name" : "", "key" : "" }
Try giving your feed name/keys some values and see how that plays out.
Otherwise what you have should work
tuddy,
I suggest you try like this:
Page.find().lean().exec(function(err,pages){
// TODO
});
I am looking for a CouchDB equivalent to "SQL joins".
In my example there are CouchDB documents that are list elements:
{ "type" : "el", "id" : "1", "content" : "first" }
{ "type" : "el", "id" : "2", "content" : "second" }
{ "type" : "el", "id" : "3", "content" : "third" }
There is one document that defines the list:
{ "type" : "list", "elements" : ["2","1"] , "id" : "abc123" }
As you can see the third element was deleted, it is no longer part of the list. So it must not be part of the result. Now I want a view that returns the content elements including the right order.
The result could be:
{ "content" : ["second", "first"] }
In this case the order of the elements is already as it should be. Another possible result:
{ "content" : [{"content" : "first", "order" : 2},{"content" : "second", "order" : 1}] }
I started writing the map function:
map = function (doc) {
if (doc.type === 'el') {
emit(doc.id, {"content" : doc.content}); //emit the id and the content
exit;
}
if (doc.type === 'list') {
for ( var i=0, l=doc.elements.length; i<l; ++i ){
emit(doc.elements[i], { "order" : i }); //emit the id and the order
}
}
}
This is as far as I can get. Can you correct my mistakes and write a reduce function? Remember that the third document must not be part of the result.
Of course you can write a different map function also. But the structure of the documents (one definig element document and an entry document for each entry) cannot be changed.
EDIT: Do not miss JasonSmith's comment to his answer, where he describes how to do this shorter.
Thank you! This is a great example to show off CouchDB 0.11's new
features!
You must use the fetch-related-data feature to reference documents
in the view. Optionally, for more convenient JSON, use a _list function to
clean up the results. See Couchio's writeup on "JOIN"s for details.
Here is the plan:
Firstly, you have a uniqueness contstraint on your el documents. If two of
them have id=2, that's a problem. It is necessary to use
the _id field instead if id. CouchDB will guarantee uniqueness, but also,
the rest of this plan requires _id in order to fetch documents by ID.
{ "type" : "el", "_id" : "1", "content" : "first" }
{ "type" : "el", "_id" : "2", "content" : "second" }
{ "type" : "el", "_id" : "3", "content" : "third" }
If changing the documents to use _id is absolutely impossible, you can
create a simple view to emit(doc.id, doc) and then re-insert that into a
temporary database. This converts id to _id but adds some complexity.
The view emits {"_id": content_id} data keyed on
[list_id, sort_number], to "clump" the lists with their content.
function(doc) {
if(doc.type == 'list') {
for (var i in doc.elements) {
// Link to the el document's id.
var id = doc.elements[i];
emit([doc.id, i], {'_id': id});
}
}
}
Now there is a simple list of el documents, in the correct order. You can
use startkey and endkey if you want to see only a particular list.
curl localhost:5984/x/_design/myapp/_view/els
{"total_rows":2,"offset":0,"rows":[
{"id":"036f3614aeee05344cdfb66fa1002db6","key":["abc123","0"],"value":{"_id":"2"}},
{"id":"036f3614aeee05344cdfb66fa1002db6","key":["abc123","1"],"value":{"_id":"1"}}
]}
To get the el content, query with include_docs=true. Through the magic of
_id, the el documents will load.
curl localhost:5984/x/_design/myapp/_view/els?include_docs=true
{"total_rows":2,"offset":0,"rows":[
{"id":"036f3614aeee05344cdfb66fa1002db6","key":["abc123","0"],"value":{"_id":"2"},"doc":{"_id":"2","_rev":"1-4530dc6946d78f1e97f56568de5a85d9","type":"el","content":"second"}},
{"id":"036f3614aeee05344cdfb66fa1002db6","key":["abc123","1"],"value":{"_id":"1"},"doc":{"_id":"1","_rev":"1-852badd683f22ad4705ed9fcdea5b814","type":"el","content":"first"}}
]}
Notice, this is already all the information you need. If your client is
flexible, you can parse the information out of this JSON. The next optional
step simply reformats it to match what you need.
Use a _list function, which simply reformats the view output. People use them to output XML or HTML however we will make
the JSON more convenient.
function(head, req) {
var headers = {'Content-Type': 'application/json'};
var result;
if(req.query.include_docs != 'true') {
start({'code': 400, headers: headers});
result = {'error': 'I require include_docs=true'};
} else {
start({'headers': headers});
result = {'content': []};
while(row = getRow()) {
result.content.push(row.doc.content);
}
}
send(JSON.stringify(result));
}
The results match. Of course in production you will need startkey and endkey to specify the list you want.
curl -g 'localhost:5984/x/_design/myapp/_list/pretty/els?include_docs=true&startkey=["abc123",""]&endkey=["abc123",{}]'
{"content":["second","first"]}
My Couchdb database as a main document type that looks something like:
{
"_id" : "doc1",
"type" : "main_doc",
"title" : "the first doc"
...
}
There is another type of document that stores user information. I want users to be able to tag documents as favorites. Different users can save the same or different documents as favorites. My idea was to introduce a favorite document to track this something like:
{
"_id" : "fav1",
"type" : "favorite",
"user_id" : "user1",
"doc_id" : "doc1"
}
It's easy enough to create a view with user_id as the key to get a list of their favorite doc IDs. E.g:
function(doc) {
if (doc.type == "favorite") {
emit(doc.user_id, doc.doc_id);
}
}
However I want to list of favorites to display the user_id, doc_id and title from the document. So output something like:
{ "key" : "user1", "value" : ["doc1", "the first doc"] }
In CouchDB 0.11 (just recently released), the include_docs=true feature allows you to look up any document in your view row. For example:
function(doc) {
if(doc.type == "favorite") {
emit(doc.user_id, {_id: doc.doc_id});
}
}
When you query your view with include_docs=true, you should see JSON like this:
// ... normal stuff
rows: [
{
"key":"user1",
"value":{"_id":"doc1"},
"doc": {
"_id" : "doc1",
"type" : "main_doc",
"title" : "the first doc"
// ...
}
},
{
// another doc, etc...
}
]
If you can't use the include_docs=true feature with v0.11, then you must have all information on-hand when you emit data for your view/map.
Instead of a traditional "join" style, consider storing a list of "favoriting" users in the main_doc documents.
{
"_id" : "doc1",
"type" : "main_doc",
"title" : "the first doc",
"favorited_by": ["user1", "user2"]
// ...
}
That way when your view runs, you can emit everything based on the information in that one document.
function(doc) {
if(doc.type == "main_doc") {
for (var a in doc.favorited_by) {
emit(doc.favorited_by[a], [doc._id, doc.title]);
}
}
}