For example suppose I have a Post schema as follows:
var Schema = new db.Schema({
title : String
, text : String
// Denormalize by using user name
, author : String
, tags: [String]
, comments: [Comment]
});
I'm trying to match a particular tag as follows:
function getPostByTag(tag, callback) {
Post.find().where({"tags.value": tag}).run(callback);
}
But it is returning everything. What am I doing wrong?
Where are you getting the "value" part of "tags.value". Shouldn't it just be:
Post.find().where({tags:tag}).run(callback);
Related
How can I set a default collection in a model schema in mongoose. Using the basic example, how can I have for example a default comment in the comments array. e.g.
var defaultComment = {title: 'add your first post'}
do I do something like this in the definition? comments: {type:[Comments], default:defaultComment }
var Comments = new Schema({
title : String
, body : String
, date : Date
});
var BlogPost = new Schema({
author : ObjectId
, title : String
, body : String
, date : Date
, comments : [Comments]
, meta : {
votes : Number
, favs : Number
}
});
mongoose.model('BlogPost', BlogPost);
According to the Mongoose documentation for Schemas, keys may specify a default value. So for your example, one might define the Comments schema as so:
var Comments = new Schema({
title : String
, body : String
, date : Date
});
var CommentsModel = mongoose.model("comments", Comments);
Then, store your default comment, and use it as the default value in your BlogPost schema:
var defaultComment = new CommentsModel({
title: "Add your first post"
});
var BlogPost = new Schema({
author : ObjectId
, title : String
, body : String
, date : Date
, comments : { type: [Comments], default: defaultComment }
, meta : {
votes : Number
, favs : Number
}
});
I hope this helps. Cheers!
I have an array inside a document of a collection called pown.
{
_id: 123..,
name: pupies,
pups:[ {name: pup1, location: somewhere}, {name: pup2, ...}]
}
Now a user using my rest-service sends the entire first entry as put request:
{name: pup1, location: inTown}
After that I want to update this element in my database.
Therefore I tried this:
var updatedPup = req.body;
var searchQuery = {
_id : 123...,
pups : { name : req.body.name }
}
var updateQuery = {
$set: {'pups': updatedPup }
}
db.pown.update(searchQuery, updateQuery, function(err, data){ ... }
Unfortunately it is not updating anythig.
Does anyone know how to update an entire array-element?
As Neil pointed, you need to be acquainted with the dot notation(used to select the fields) and the positional operator $ (used to select a particular element in an array i.e the element matched in the original search query). If you want to replace the whole element in the array
var updateQuery= {
"$set":{"pups.$": updatedPup}
}
If you only need to change the location,
var updateQuery= {
"$set":{"pups.$.location": updatedPup.location}
}
The problem here is that the selection in your query actually wants to update an embedded array element in your document. The first thing is that you want to use "dot notation" instead, and then you also want the positional $ modifier to select the correct element:
db.pown.update(
{ "pups.name": req.body.name },
{ "$set": { "pups.$.locatation": req.body.location }
)
That would be the nice way to do things. Mostly because you really only want to modify the "location" property of the sub-document. So that is how you express that.
I'm dont think that this is a Meteor specific question, but rather around mongo and building mongo queries.
If I have the following structure,
{
username : someName,
contacts : [
{
userid : asdfae33rtqqxxx,
name : contactName,
status : friend
}
{
userid : asdfae33rtqqxxx,
name : anotherName,
status : pending
}
{
userid : asdfae33rtqqxxx,
name : contactName,
status : blocked
}
]
}
How could I pass in values from this array into a query against the users collection, to a) get the users in this array, or b) get all users in this array from the users collection with a particular status.
If this is not possible, how should I adjust my schema in order to make these sorts of queries possible?
This function will return a Meteor.users cursor based on an array of contacts and an optionally required status:
var usersByContacts = function(contacts, requiredStatus) {
var userIds = _.chain(contacts)
.map(function(c) {
if (requiredStatus) {
if (c.status === requiredStatus)
return c.userid;
} else {
return c.userid;
}
})
.compact()
.value();
return Meteor.users.find({_id: {$in: userIds}});
};
You can use it like this:
var users1 = usersByContacts(thing.contacts);
var users2 = usersByContacts(thing.contacts, 'pending');
This assumes thing has the schema referenced in your question. Also note that if you find this is a common pattern in your code, you should consider turning usersByContacts into a transform.
I have mongoose schema as:
var Organization = new Schema({
name: String,
address: {
street : String,
city: String
}
}, { collection: 'organization' });
How do I update only street part of address for an organization via mongoose?
I can't find any docs that cover this simple case so I can see why you're having trouble. But it's as simple as using a $set with a key that uses dot notation to reference the embedded field:
OrganizationModel.update(
{name: 'Koka'},
{$set: {'address.street': 'new street name'}},
callback);
Now you can update directly .
OrganizationModel.update(
{name: 'Koka'},
{'address.street': 'new street name'},
callback);
Using Document set also, specified properties can be updated. With this approach, we can use "save" which validates the data also.
doc.set({
path : value
, path2 : {
path : value
}
}
Example: Update Product schema using Document set and save.
// Update the product
let productToUpdate = await Product.findById(req.params.id);
if (!productToUpdate) {
throw new NotFoundError();
}
productToUpdate.set({title:"New Title"});
await productToUpdate.save();
Note - This can be used to update the multiple and nested properties also.
I am trying to insert nested documents in to a MongoDB using C#. I have a collection called categories. In that collection there must exist documents with 2 array, one named categories and one named standards. Inside those arrays must exist new documents with their own ID's that also contain arrays of the same names listed above. Below is what I have so far but I am unsure how to proceed. If you look at the code what I want to do is add the "namingConventions" document nested under the categories array in the categories document however namingConventions must have a unique ID also.
At this point I am not sure I have done any of this the best way possible so I am open to any and all advice on this entire thing.
namespace ClassLibrary1
{
using MongoDB.Bson;
using MongoDB.Driver;
public class Class1
{
public void test()
{
string connectionString = "mongodb://localhost";
MongoServer server = MongoServer.Create(connectionString);
MongoDatabase standards = server.GetDatabase("Standards");
MongoCollection<BsonDocument> categories = standards.GetCollection<BsonDocument>("catagories");
BsonDocument[] batch = {
new BsonDocument { { "categories", new BsonArray {} },
{ "standards", new BsonArray { } } },
new BsonDocument { { "catagories", new BsonArray { } },
{ "standards", new BsonArray { } } },
};
categories.InsertBatch(batch);
((BsonArray)batch[0]["categories"]).Add(batch[1]);
categories.Save(batch[0]);
}
}
}
For clarity this is what I need:
What I am doing is building a coding standards site. The company wants all the standards stored in MongoDB in a tree. Everything must have a unique ID so that on top of being queried as a tree it can be queried by itself also. An example could be:
/* 0 */
{
"_id" : ObjectId("4fb39795b74861183c713807"),
"catagories" : [],
"standards" : []
}
/* 1 */
{
"_id" : ObjectId("4fb39795b74861183c713806"),
"categories" : [{
"_id" : ObjectId("4fb39795b74861183c713807"),
"catagories" : [],
"standards" : []
}],
"standards" : []
}
Now I have written code to make this happen but the issue seems to be that when I add object "0" to the categories array in object "1" it is not making a reference but instead copying it. This will not due because if changes are made they will be made to the original object "0" so they will not be pushed to the copy being made in the categories array, at least that is what is happening to me. I hope this clears up what I am looking for.
So, based on your latest comment, it seems as though this is the actual structure you are looking for:
{
_id: ObjectId(),
name: "NamingConventions",
categories: [
{
id: ObjectId(),
name: "Namespaces",
standards: [
{
id: ObjectId(),
name: "TitleCased",
description: "Namespaces must be Title Cased."
},
{
id: ObjectId().
name: "NoAbbreviations",
description: "Namespaces must not use abbreviations."
}
]
},
{
id: ObjectId(),
name: "Variables",
standards: [
{
id: ObjectId(),
name: "CamelCased",
description: "variables must be camel cased."
}
]
}
]
}
Assuming this is correct, then the below is how you would insert one of these:
var collection = db.GetCollection("some collection name");
var root = new BsonDocument();
root.Add("name", "NamingConventions");
var rootCategories = new BsonArray();
rootCategories.Add(new BsonDocument
{
{ "id": ObjectId.GenerateNewId() },
{ "name", "Namespaces" },
{ "standards", new BsonArray() }
});
root.Add("categories", rootCategories);
//etc...
collection.Save(root);
Hope that helps, if not, I give up :).
So, I guess I'm confused by what you are asking. If you just want to store the namingConventions documents inside the array, you don't need a collection for them. Instead, just add them to the bson array and store them.
var categoriesCollection = db.GetCollection<BsonDocument>("categories");
var category = new BsonDocument();
var namingConventions = new BsonArray();
namingConventions.Add(new BsonDocument("convention1", "value"));
category.Add("naming_conventions", namingConventions);
categoriesCollection.Insert(category);
This will create a new document for a category, create an array in it called naming_conventions with a single document in it with an element called "convention1" and a value of "value".
I also am not quite sure what you are trying to accomplish. Perhaps if you posted some sample documents in JSON format we could show you the C# code to write documents that match that.
Alternatively, if you wish to discuss your schema, that could also be better done in the context of JSON rather than C#, and once a schema has been settled on then we can discuss how to write documents to that schema in C#.
One thing that didn't sound right in your original description was the statement "in that collection must exist 2 arrays". A collection can only contain documents, not arrays. The documents themselves can contain arrays if you want.
var filter = Builders<CollectionDefination>.Filter.Where(r => r._id== id);
var data = Builders<CollectionDefination>.Update.Push(f=>
f.categories,categoriesObject);
await _dbService.collection.UpdateOneAsync( filter,data);
Note: Make sure embedded document type [Categories] is array.