I am working with RavenDB documents. I need to change a field in all the documents at once. I read there is something called set based updates in Raven DB documentation. I need a little help to put me in right direction here.
A patron Document looks something like this:
{
"Privilege": [
{
"Level": "Gold",
"Code": "12312",
"EndDate": "12/12/2012"
}
],
"Phones": [
{
"Cell": "123123",
"Home": "9783041284",
"Office": "1234123412"
}
]
{
In Patrons document collection, there is a Privilege.Level field in each doc. I need to write a query to update it to "Gold" for all documents in that Patrons collection. This is what I know so far. I need to create an Index (ChangePrivilegeIndex) first:
from Patrons in docs.patrons
select new {Patrons.Privilege.Level}
and then write a curl statement to patch documents all at once something like this:
PATCH http://localhost:8080/bulk_docs/ChangePrivilegeIndex
[
{ "Type": "Set", "Name": "Privilege.Level", "Value": "Gold"}
]
I need help to get this to work .. thank you. I know there are lots of loose ends in the actual scripts.. that's why its not working. Can some one look at the scenario and the script above to put me in right direction.
Related
I would like to extend the standard ListAPIView by adding allowed actions to each item so that the JSON returned on GET /books/ would approximately look as follows:
[
{
"ID": 1,
"name": "Animal Farm",
"author": "George Orwell",
"actions": [
"detail": {
"method": "GET"
"uri": "/books/1"
},
"remove": {
"method": "DELETE"
"uri": "/books/1"
}
...
]
},
...
]
By having such an "action list", I can easily tell the frontend which actions are currently allowed so it can e. g. include only buttons for those actions.
I went through the DRF docs and could not find a similar functionality. Shall I write it from scratch or is there a 3rd party plugin that could possibly help me? And when writing this from scratch, how would you design (=where to write the code of) such a feature?
DRF has support for that when you use the OPTIONS method, you can find more info here.
You could take a look into how this SimpleMetadata function creates the list of actions and either base yourself on it to write yours from scratch, or just find a way to call it to render the action list.
I'm not sure, if there is such plugin in DRF (maybe something for serializers?).
If writing from scratch, you should override your get() method ListAPIView (or list() method of mixins.ListModelMixin)
Is there any way of getting a list of albums for an artist (band), along with a link to album art and runtime?
I've been given this endpoint, but the data it returns is confusing:
http://musicbrainz.org/ws/2/recording?query=artist:%22Queen%22%20and%20type:album&fmt=json
The data isn't really organized around albums, and the "length" data returns something like 203000. But it's better if you see it in context, so here's the first bit of it (sorry I couldn't get it indented):
{
"created": "2018-02-17T03:47:57.052Z",
"count": 9533710,
"offset": 0,
"recordings": [
{
"id": "c2e919f7-ecb9-4fdf-9162-3c26d0127fa0",
"score": "100",
"title": "Son and Daughter",
"length": 203000,
"video": null,
"artist-credit": [
{
"artist": {
"id": "0383dadf-2a4e-4d10-a46a-e9e041da8eb3",
"name": "Queen",
"sort-name": "Queen",
"disambiguation": "UK rock group",
"aliases": [
{
"sort-name": "Queen + Adam Lambert",
"name": "Queen + Adam Lambert",
"locale": null,
"type": null,
"primary": null,
"begin-date": "2011",
"end-date": null
}
]
}
}
],
"releases": [
{
"id": "bb19abaf-80b3-4a3e-846d-5f12b12af827",
"title": "Queen",
"status": "Official",
"release-group": {
"id": "810068af-2b3c-3e9c-b2ab-68a3f3e3787d",
"primary-type": "Album"
},
"date": "1994",
"country": "NL",
"release-events": [
{
"date": "1994",
"area": {
"id": "ef1b7cc0-cd26-36f4-8ea0-04d9623786c7",
"name": "Netherlands",
"sort-name": "Netherlands",
"iso-3166-1-codes": [
"NL"
]
}
}
],
"track-count": 10,
"media": [
{
"position": 1,
"format": "CD",
"track": [
{
"id": "3a26455e-2660-30dc-a652-6a2b40f1fbe5",
"number": "8",
"title": "Son and Daughter",
"length": 203400
}
],
"track-count": 10,
"track-offset": 7
}
]
},
{
"id": "1783da6a-9315-3602-a488-1738eb733a0f",
"title": "Queen",
"status": "Official",
"release-group": {
"id": "810068af-2b3c-3e9c-b2ab-68a3f3e3787d",
"primary-type": "Album"
},
"date": "1973-09-04",
"country": "US",
"release-events": [
{
"date": "1973-09-04",
"area": {
"id": "489ce91b-6658-3307-9877-795b68554c98",
"name": "United States",
"sort-name": "United States",
"iso-3166-1-codes": [
"US"
]
}
}
],
If someone can explain this data to me, then I don't need another endpoint. But I've been hunting around the musicbrainz docs and they're not super helpful.
Preferably it would be with one call, but I can do successive calls if necessary.
Thanks for your help.
First off:
Is there any way of getting a list of albums for an artist (band), along with a link to album art and runtime?
Yes, definitely.
First you will want to find the artist, say, the Queen that did Bohemian Rhapsody. They're identified with MusicBrainz Artist ID "0383dadf-2a4e-4d10-a46a-e9e041da8eb3", so you can do a browse request for Releases by this artist: https://musicbrainz.org/ws/2/release/?artist=0383dadf-2a4e-4d10-a46a-e9e041da8eb3&inc=recordings&fmt=json (note the inc=recordings)
This gives you most of what you are asking for. A list of releases and their runtime—kind of. Each Release should have one or more medium properties that in turn have a track-list with a number of tracks. The sum of the length of each of these tracks is what makes up the runtime (the length is given in milliseconds).
For cover art, you may notice that the output has a cover-art-archive property. For cover art, MusicBrainz uses Cover Art Archive which uses MusicBrainz IDs as identifiers. The cover-art-archive attribute states whether any cover art exists in Cover Art Archive and a few details about this—e.g., does CAA have any images at all (artwork)? Does it have a back image (back) and/or a front image (front)? How many images are there in all for the release (count)? If the cover-art-archive→artwork is true, we can go on and fetch cover art from the CAA. The CAA's API is really simple: to get the "front" image of a release, say the 1974 UK single "Killer Queen" that has MusicBrainz Release ID "a2d12ee8-9aeb-4d91-bfab-5c21f7a577fc", you can simply do https://coverartarchive.org/release/a2d12ee8-9aeb-4d91-bfab-5c21f7a577fc/front
You can also do https://coverartarchive.org/release/a2d12ee8-9aeb-4d91-bfab-5c21f7a577fc to get a JSON document with more details about what cover art images are available (e.g., this one has two images: one Front+Medium and one Back+Medium image).
The Cover Art Archive API is documented at https://musicbrainz.org/doc/Cover_Art_Archive/API and the MusicBrainz API/web service documentation can be found at https://musicbrainz.org/doc/Development/XML_Web_Service/Version_2
Note that using browse requests you can page through the results using offset and vary the amount of results per query using limit, see the "Paging" section under the browse request section in the MusicBrainz WS documentation.
Secondly: Though you don't ask about this directly, you're using a search query using a generic term in your question, so I thought I'd talk about this for a bit. In MusicBrainz everything is identified using MusicBrainz identifiers (IDs). (I kind of mentioned them in the first section too.)
The reason for this is that many, many names are not unique. There are as of this writing three unique artists known as "Queen" in MusicBrainz: https://musicbrainz.org/search?query=%22queen%22&type=artist&method=advanced – not counting any of the 321 other artists that have "queen" as part of their name. Without more information, it is not possible for MusicBrainz to know which of them you want to find out information from, so your first step will likely be to somehow either narrow the search (e.g., add type:group narrows the search to 123 results, using country:gb limits to 21 results, doing both gives 11 results (see the search syntax documentation for more details)) or somehow filter afterwards.
Once you've narrowed it down to the specific artist you want, you can continue with the steps outlined above to get the details you want. The steps for narrowing it down will depend on your specific application/use case.
Finally: You seem to have some missing understanding at the asbstract level about how MusicBrainz's data is structured. E.g., all of the above is assuming that by album you mean a specific released version like the 1974 UK "Killer Queen" single, and not a more generic concept of a release like any version of the "Killer Queen" single, which in MusicBrainz terminology would be a Release Group.
https://musicbrainz.org/doc/MusicBrainz_Entity is a list of entities used in MusicBrainz. Understanding the differences between a Release Group and a Release as well as between Tracks and Recordings (and Works) will put you in a much better position to effectively use the web service and the MusicBrainz data in general.
https://musicbrainz.org/doc/MusicBrainz_Database/Schema is a introduction to how MusicBrainz is structured. Knowing how artist credits, ("advanced") relationships, and mediums play into things is also likely to save you a lot of headache later.
You need to understand the format of the data returned, copy the result in to a JSON formatting service such as https://jsonformatter.curiousconcept.com/
You will then realise you have multiple artists in the returned data, which is why it's not as simple as "albums by artist"
I’m guessing the "length" data is in milliseconds.
I'm working on an app, which is supposed to show data from two nodes(Firebase). Firebase DB is structured as:
{
"College": {
"4F2EAB65": {
"id": "4F2EAB65",
"name": "SomeCollege"
},
"A3C2ED31": {
"id": "A3C2ED31",
"name": "OtherCollege"
},
"F967B5A0": {
"id": "F967B5A0",
"name": "CoolCollege"
}
},
"Student": {
"3E20545B": {
"college-ID": "4F2EAB65",
"id": "3E20545B",
"name": "A"
},
"6FDEE194": {
"college-ID": "F967B5A0",
"id": "6FDEE194",
"name": "B"
}
}
I want to fetch student details having details: "id", "name", "college-ID", "college-Name"(Need to fetch "college-Name" by "college-ID").
I've achieved this using for loop at front end. Is there any way to get this achieved at Firebase server, also can we make something like join (SQL).
Thanks.
There is no support for server-side joins in the Firebase Realtime Database. Client-side joins are quite normal.
The alternative is to duplicate the data upon writing, so that you don't have to read from two locations.
What's best for your application is a matter of personal preference, your comfort level with the code involved vs data duplication, and the use-cases of your app.
Client-side jons are likely not as slow as you may think. See http://stackoverflow.com/questions/35931526/speed-up-fetching-posts-for-my-social-network-app-by-using-query-instead-of-obse/35932786#35932786
I am building an app that give users the ability to construct there own graphs. I have been using parameters for all queries and creates. But when I want to give users the ability to create a node where they can also Label it anything they want(respecting neo4j restrictions on empty string labels). How would I parameterize this type of transaction?
I tried this:
.CREATE("(a:{dynamicLabel})").WithParams(new {dynamicLabel = dlabel})...
But this yields a syntax error with neo. I am tempted to concatenate, but am worried that this may expose an injection risk to my application.
I am tempted to build up my-own class that reads the intended string and rejects any type of neo syntax, but this would limit my users a bit and I would rather not.
There is an open neo4j issue 4334, which is a feature request for adding the ability to parameterize labels during CREATE.So, this is not yet possible.
That issue contains a comment that suggests generating CREATE statements with hardcoded labels, which will work. It is, unfortunately, not as performant as using parameters (should it ever be supported in this case).
I searched like hell and finally found it out.
you can do it like that:
// create or update nodes with dynamic label from import data
WITH "file:///query.json" AS url
call apoc.load.json(url) YIELD value as u
UNWIND u.cis as ci
CALL apoc.merge.node([ ci.label ], {Id:ci.Id}, {}, {}) YIELD node
RETURN node;
The JSON looks like that:
{
"cis": [
{
"label": "Computer",
"Id": "1"
},
{
"label": "Service",
"Id": "2"
},
{
"label": "Person",
"Id": "3"
}
],
"relations": [
{
"end1Id": "1",
"Id": "4",
"end2Id": "2",
"label": "USES"
},
{
"end1Id": "3",
"Id": "5",
"end2Id": "1",
"label": "MANAGED_BY"
}
]
}
If you are using a Java client, then you can do it like this.
Node node = GraphDatabaseService.createNode();
Label label = new Label() {
#Override
public String name() {
return dynamicLabelVal;
}
};
node.addLabel(label);
You can then have a LabelCache which will avoid Label object creation for every node.
Quite simply, this question or answer does not exist anywhere I have looked.
The objective is to reindex a node to update it's latitude and longitude properties.
The plugin I'm using to accomplish Geospatial operations in neo4j is called Spatial
Here is my setup
I create a pointlayer:
POST http://localhost:7474/db/data/ext/SpatialPlugin/graphdb/addSimplePointLayer
{
"layer" : "geom",
"lat" : "geolocation.lat",
"lon" : "geolocation.lon"
}
I then create a geom spatial index:
POST http://localhost:7474/db/data/index/node/
{
"name": "geom",
"config": {
"provider": "spatial",
"geometry_type": "point",
"lat": "geolocation.lat",
"lon": "geolocation.lon"
}
}
I finally add the node to the index:
POST http://localhost:7474/db/data/index/node/geom
{
"value": "dummy",
"key": "dummy",
"uri": "http://localhost:7474/db/data/node/5734"
}
I have a theory about how reindexing might be accomplished. First, I would remove the node from the geospatial index and then re-add it. But I'm concerned this may mess something up. I've read elsewhere that removing indexes and then adding them can create problems.
What is the proper way to reindex a node?
It looks as if you can just call POST on the index again. I don't know what the implications of this are yet. I also don't know if it creates a new index/node. It does seem to update correctly from my limited testing.
Example:
POST http://localhost:7474/db/data/index/node/geom
{
"value": "dummy",
"key": "dummy",
"uri": "http://localhost:7474/db/data/node/5734"
}
You can verify that the index node was not duplicated by running the following Cypher query.
MATCH (node { id: 5734 })
RETURN node
Important: The above id is NOT to be confused with the actual ID of the geospatial node itself. It is a property for referring to the node that you indexed.