I want to insert one or more attributes into the existing JSON. Here's the basic format.
var resultData = {
"result" : "OK",
"data" : [
{"name1" : "value1"},
{"name2" : "value2"}
]
};
And I want to insert {"name3" : "value3"} into the end of the data field. The result should look like this.
var resultData = {
"result" : "OK",
"data" : [
{"name1" : "value1"},
{"name2" : "value2"},
{"name3" : "value3"}
]
};
How do I do this? I know how to add an attribute to the resultData or resultData.result or resultData.data.name1 or etc. However, I couldn't find a way to add an attribute to the resultData.data.
You can do:
resultData.data[3] = {"name4" : "value4"}
That would add a new element on the 4th position.
And like Sigorilla just answered before me, .push() will always add it one the end of your object.
You don't need to do resultData["data"].push() though, as you can just use resultData.data.push() I think.
You can use push(): resultData["data"].push({"name3": "value3"});
Related
I am new to MongoDB and would like to use Meteor Templates to display the queried data in a table.
I have a collection named "infoData" with this structure:
First Document:
{
"_id" : "A-89273498720",
"myItems" : [
{
"itemId" : "item_1",
"username" : "Homer",
"purpose" : "justBecause",
},
{
"itemId" : "item_2",
"username" : "March",
"purpose" : "justBecause2",
},
{
"itemId" : "item_3",
"username" : "Maggie",
"purpose" : "justBecause3",
}
]
}
Second Document:
{
"_id" : "B-564548461117",
"myItems" : [
{
"itemId" : "item_4",
"username" : "Lisa",
"purpose" : "justBecause4",
},
{
"itemId" : "item_5",
"username" : "Lisa",
"purpose" : "justBecause5",
},
{
"itemId" : "item_6",
"username" : "Bart",
"purpose" : "justBecause5",
}
]
}
Now I need to retrieve "itemId" as well as "username" and "purpose" with the "itemId" as a query operator. The "itemId" is unique. My first problem is to get the data. For example I tried this to get the single "itemId" field "item_2":
infoData.findOne({"myItems.itemId": "item_2"}, {_id: 0, 'myItems.$': 1})
which gets the same result as
infoData.findOne(
{
'myItems.itemId': "item_2"
},
{
'_id': 0, 'myItems': {$elemMatch: {'itemId': "item_2"}}
})
I am unsure if this is the result I need, because when I put this query in JSON.stringify() to see the data in the console I see all fields and objects within the array of the doc which contains "item_2" and not only the data "item_2" of the field "itemId". A possibility to get all fields "itemId", "username" and "purpose" of the query (only the object containing item_2) so that I can iterate over it later in a table would also work for me.
The second issue is that I need to display the data in a table.
So I wrote this helper:
'itemInfoDisplay': function() {
if (Meteor.userId()) {
var itemInfos= infoData.findOne(
{"myItems.itemId": "item_2"}, {_id: 0, 'myItems.$': 1});
return itemInfos
}
}
and want to show the data in a table:
{{#each itemInfoDisplay}}
{{#each myItems}}
<tr>
<td><h4>{{ itemId }}</h4></td>
</tr>
{{/each}}
{{/each}}
I know there is something wrong with the code and also with the HTML template. I guess that the result of the mongoDB query is not an array? Is it possible to make it to one? Is the used mongo query the correct solution for my needs?
At the end I just need to get all data which is assigned to a specific "itemId" and display it in a table. I would appreciate anything that helps.
I can think of two ways to do this. The first is to use a projection as mentioned in this post: Retrieve only the queried element in an object array in MongoDB collection
However, it appears you're using that $elemMatch format. If it's not working, not sure if you want to try find() rather than findOne(). There may be a difference in the way Meteor is sending the query to mongodb.
If that doesn't work, the second way is a little bit of a hack but will work. We take advantage of the fact that findOne (unlike find) is synchronous on the client. So we can get the record, then manually do a forEach to only get the appropriate array elements and return that array. Something like this:
var itemInfos= infoData.findOne({"myItems.itemId": "item_2"}, {_id: 0, 'myItems.$': 1});
var items = [];
itemInfos.myItems.forEach(function(myItem) {
if (myItem.itemId == "item_2") {
items.push(myItem);
};
});
return items;
If you use lodash, you can skip the forEach loop and use filter:
return( _.filter(itemInfos.myItems, {itemId: "item_2"}) );
The ideal way would be to restrict the data at the query level, but if that doesn't work option 2 should.
I have a mongo collection workspaces in my MongoDB which consist of records that looks like as follows:
{
"_id" : ObjectId("58bdc4a13504f5ed743ad025"),
"name" : "My workspace",
"user_id" : ObjectId("58b6cf53988a874af070fd3b"),
"uploads" : [
{
"original" : "DE-20__450_GG_5002_N23_994__0136.tif"
},
{
"original" : "DE-20__450_GG_5002_N23_994__0134.png"
},
{
"original" : "DE-20__450_GG_5002_N23_994__0136.png"
},
{
"original" : "DE-20__450_GG_5002_N23_994__0134.tif"
}
]
}
Now my objective is that i want to append something in one of record of array uploads with the match criteria of original field value. For example i want to append "pseg" : "DE-20__450_GG_5002_N23_994__0136.pseg.tif" to the {"original" : "DE-20__450_GG_5002_N23_994__0136.tif"} collection in following way:
{
"_id" : ObjectId("58bdc4a13504f5ed743ad025"),
"name" : "Objective",
"user_id" : ObjectId("58b6cf53988a874af070fd3b"),
"uploads" : [
{
"original" : "DE-20__450_GG_5002_N23_994__0136.tif",
"pseg" : "DE-20__450_GG_5002_N23_994__0136.pseg.tif"
},
{
"original" : "DE-20__450_GG_5002_N23_994__0134.png"
},
{
"original" : "DE-20__450_GG_5002_N23_994__0136.png"
},
{
"original" : "DE-20__450_GG_5002_N23_994__0134.tif"
}
]
}
i tried using $elemMatch and then i added $addToSet in following way:
db.getCollection('workspaces').update({"_id": ObjectId("58bdc4a13504f5ed743ad025"),"uploads": {$elemMatch: {"original": "DE-20__450_GG_5002_N23_994__0136.tif"}}},{$addToSet:{"uploads.$": {"pseg" : "DE-20__450_GG_5002_N23_994__0136.pseg.tif"}}})
but it gives me following error:
Cannot apply $addToSet to a non-array field. Field named '0' has a non-array type object in the document _id: ObjectId('58bdc4a13504f5ed743ad025')
I think i crafted the query wrong can anyone tell me what is wrong and how can i solve it?
Sorry for my bad english :) hope you understood what i said.
Here is the correct syntax. You have to use $set with postional operator to reach the element.
db.getCollection('workspaces').update(
{"_id": ObjectId("58bdc4a13504f5ed743ad025"),"uploads": {$elemMatch: {"original": "DE-20__450_GG_5002_N23_994__0136.tif"}}},
{$set:{"uploads.$.pseg" : "DE-20__450_GG_5002_N23_994__0136.pseg.tif"}})
More information here https://docs.mongodb.com/manual/reference/operator/update/positional/#update-documents-in-an-array
You can simplify your query criteria. You don't need to use $elemMatch operator for single query condition. You can use dot notation.
db.getCollection('workspaces').update(
{"_id": ObjectId("58bdc4a13504f5ed743ad025"),"uploads.original": "DE-20__450_GG_5002_N23_994__0136.tif"},
{$set:{"uploads.$.pseg" : "DE-20__450_GG_5002_N23_994__0136.pseg.tif"}})
More information here
https://docs.mongodb.com/manual/reference/operator/query/elemMatch/#single-query-condition
The document structure is as follows:
{
"_id" : "V001-99999999",
"vendor_number" : "V001",
"created_time" : ISODate("2016-04-26T22:15:34Z"),
"updated_time" : ISODate("2016-06-07T21:45:46.413Z"),
"items" : [
{
"sku" : "99999999-1",
"status" : "ACTIVE",
"listing_status" : "LIVE",
"inventory" : 10,
"created_time" : ISODate("2016-05-14T22:15:34Z"),
"updated_time" : ISODate("2016-05-14T20:42:21.753Z"),
},
{
"sku" : "99999999-2",
"status" : "INACTIVE",
"listing_status" : "LIVE",
"inventory" : 10,
"created_time" : ISODate("2016-04-26T22:15:34Z"),
"updated_time" : ISODate("2016-06-06T20:42:21.753Z"),
}
]
}
I want to obtain the sku from the item, the conditions are:
1) "vendor_number" = "XXX"
2) items.status = "ACTIVE" AND items.updated_time < [given_date]
Result example:
"sku" : "99999999-2"
or csv:
"sku","99999999-2"
Thank you for your support.
This should be what you want. Although I'm assuming you wanted "status": "active"?
db.getCollection('collection').aggregate([
{ $match: { "vendor_number": "XXXX" } },
{ $project: {
"items": {
$filter: {
input: "$items",
as: "item",
cond: { $eq: ["$$item.status", "ACTIVE"] } // or maybe ["$$item.listing_status", "LIVE"] ?
}
}
}
},
{ $project: { "items.sku": true } }
])
I love using aggregation to manipulate stuff. It's great all the things you can do with it. So here's what's going on:
The first part is simple. The $match step in the aggregation pipeline says just give me documents where vendor_number is "XXXX".
The next part is a bit hairy. The first projection step creates a new field, called "items", I could have called it "results" or "bob" if I wanted to. The $filter specifies which items should go into this new field. The new "items" field will be an array that will have all the results from the previous items field, hence the input: "$items", where you're using the keyword "item" to represent each input item that comes into the filter. Next, the condition says, for each item, only put it in my new "items" array if the item's status is "ACTIVE". You can change it to ["$$items.listing_status", "LIVE"] if that's what you needed. All of this will pretty much give you you're result.
The last project just get's rid of all other fields except for items.sku in each element in the new "items" array.
Hope this help. Play around with it and see what else you can do with the collection and aggregation. Let me know if you need any more clarification. If you haven't used aggregation before, take a look at the aggregation docs and the list of pipeline operators you can use with aggregation. Pretty handy tool.
I have a collection with the following document:
{ "_id" : "DzQuhq22NhQm5waCm", "title" : "Test", "users" : [ "wCxEmesi2M73dLze4" ], "userId" : "htMZEZTMxsQXq6sRD", "createdAt" : ISODate("2015-10-05T12:09:34.852Z") }
The attribute users is an array which contains also userIds.
Now I want to find this document if my value is either within the users array or matches the userId. So, this document should be returned if my value is htMZEZTMxsQXq6sRD or wCxEmesi2M73dLze4.
I tried the following:
db.test.find({userId: val}, {users: {$in: val}); but this does not work.
Thanks in advance.
Try this:
db.getCollection('TESTCOLLECTION').find({$or:[{'userId':'htMZEZTMxsQXq6sRD '},{'users':'wCxEmesi2M73dLze4'}]})
I'm trying to build a model that dynamically updates Session variables in a Meteor project. I know that plain JSON should not be stored within backbone models, so I have a Special model set up like so:
initialize : function () {
// Log the changed properties
this.on('change', function (model, options) {
for ( var i in options.changes)
this.display(i);
Session.set('NewSpecial', model);
});
},
//Attributes
defaults: {
"Product" : null,
"ShortDescription" : null,
"Category" : "food",
"Price" : new PriceModel,
"Date" : new DateModel,
"Uses" : 0,
"Tags" : [],
"Contributor" : null
},
With "Price" and "Date" being stored in their own models:
//Price model for use within Special
var PriceModel = Backbone.Model.extend({
defaults : {
"Regular" : null,
"Special" : null,
"PercentOff" : null
}
});
//Date model for use within Special
var DateModel = Backbone.Model.extend({
defaults : {
"StartTime" : null,
"EndTime" : null,
"HumanTimeRange" : null
}
});
As shown, when the attributes of the Special model change, it should call display for the attribute that changed, and then set the Session var to the model. If my DateModel or PriceModel change however, it doesn't appear to trigger a change event on the Special model. Should each "DateModel" and "PriceModel" have their own this.on('change', ...) methods that call Special.set(attribute, thisModel) methods? Or is there a different way to go about this?
I see a couple problems.
First of all, your defaults:
defaults: {
"Product" : null,
"ShortDescription" : null,
"Category" : "food",
"Price" : new PriceModel,
"Date" : new DateModel,
"Uses" : 0,
"Tags" : [],
"Contributor" : null
}
That will end up with one PriceModel, one DateModel, and one tags array being shared by all instances of that model. A defaults object is shallow copied and merged into the model's attributes, none of the values in defaults are cloned or duplicated, they're just copied over as-is. If you want distinced Price, Date, and Tags values then use a function for defaults:
defaults: function() {
return {
"Product" : null,
"ShortDescription" : null,
"Category" : "food",
"Price" : new PriceModel,
"Date" : new DateModel,
"Uses" : 0,
"Tags" : [],
"Contributor" : null
};
}
The second problem is that set has a fairly simplistic view of what change means. If you have a look at the source for set, you'll see this:
// If the new and previous value differ, record the change. If not,
// then remove changes for this attribute.
if (!_.isEqual(prev[attr], val) || (_.has(now, attr) !== _.has(prev, attr))) {
this.changed[attr] = val;
if (!silent) this._pending[attr] = true;
} else {
delete this.changed[attr];
delete this._pending[attr];
if (!changing) delete this._changes[attr];
}
The _.isEqual won't recognize that something has changed inside your Price or Date or that you've added or removed something from Tags. If you do things like this:
p = new PriceModel(...);
m.set('Price', p)
then m will noticed that Price has changed but if you:
p = m.get('Price');
p.set(...);
m.set('Price', p);
then m won't recognize that Price has changed; your model won't automatically bind to events on Price so it won't notice the p.set(...) call and it won't recognize m.set('Price', p) as a change since that's little more than a fancy way of saying p = p.
You can solve part of this change problem by not giving set a Tags array that came from get; make a copy, change the copy, and then hand the updated copy to set. The half can be handled by binding to "change" events on the contained Price and Date models and forwarding them similar to how collections do it, something like this:
initialize: function() {
this.attributes.Price.on(
'all',
function(ev, model, opts) { this.trigger(ev, model, opts) },
this
);
//...
}
You'd want to provide your own set implementation in case someone did a set('Price', some_new_object) and you need to rebind your forwarder.