I am currently working with the Algolia search API and I am unable to figure out how I would limit the results by key value searching + query string. By this i mean this.
I have a list of properties.
Each property belongs to a client.
Within the application If i am looking at a client information card and I want to search for a property that client owns It would make more sense to limit the results to the client and then look for the query string.
I am using MongoDB as my DB and storing the client id as a sub document like so
//Property Document
{
_id : "randomID"
client : {
_id : "randomID",
name : "ClientName"
}
}
If you want to restrict the search to a specific client, I would go for facet filtering to restrict the search to that client only.
Add client._id in the attributesForFaceting in your index settings
Filter your searches with the facetFilters=client._id:MYCLIENTID query parameter
Then, you should also take a look at the Secured API keys which are able to encode such restriction in a secure way (so the end-user cannot patch the JS code and work-around the filtering).
There is parameter called restrictSearchableAttributes[link] to restrict, at query time, search to some attributes only. Nevertheless, in your case I think you'd get more accurate results by putting each client info into a different record (+ the info of the related document).
Related
I'm building an address-book app that uses a back-end Cloudant database. The database stores 3 types of documents:
-> User Profile document
-> Group document
-> User-to-Group Link document
As the names of the document go, there are users in my database, there are groups for users(like whatsapp), and there are link documents for each user to a group (the link document also stores settings/privileges of that user in that group).
My client-side app on login, queries cloudant for the user document, and each group document using view collation over the link documents of that user.
Then using the groups that I have identified above, I find all the other users of that group.
Now, the challenge is that I need to monitor any changes on the group and user documents. I am using pouchdb on the app side, and can invoke the 'changes' API against the ids of all the group and user documents. But the scale of this can be maybe 500 users in each group, and a logged in user being part of 10-50 groups. That multiplied to 1000s of users will become a nightmare for the back-end to support.
Is my scalability concern warranted? Or is this normal for cloudant?
If I understand your schema correctly, you documents of this form:
{
_id: "user:glynn",
type: "user",
name: "Glynn Bird"
}
{
_id: "group:Developers",
type: "group",
name: "Software Developers"
}
{
_id: "user:glynn:developers"
}
In the above example, the primary key's sorting allows a user and all of its memberships to be retrieved by using startkey and endkey parameters do the database's _all_docs endpoint.
This is "scalable" in the sense that if is efficient for Cloudant retrieve data from a primary or secondary index because the index is held in a b-tree so data with adjacent keys is store next to each other. A limit parameter can be used to paginate through larger data sets.
yes the documents are more or less how you've specified.
Link documents are as follows:
{
"_id": <AutoGeneratedID>,
"type": "link",
"user": user_id,
"group": group_id
}
I've written the following view map function:
if(type == "link") {
emit(doc.user, {"_id": doc.user});
emit([doc.user, doc.group], {"_id": doc.group});
emit([doc.group, doc.user], {"_id": doc.user});
}
using the above 3 indexes and include-docs=true, 1st lets me get my logged-in user document, 2nd lets me get all group documents for my logged-in user (using start and end key), and 3rd lets me get all other user documents for a group (using start and end key again).
Fetching the documents is done, but now I need to monitor changes on users of each group, for this, don't I need to query the changes API with array of user ids ? Is there any other way ?
Cloudant retrieve data from a primary or secondary index because the
index is held in a b-tree so data with adjacent keys is store next to
each other
Sorry, I did not understand this statement ?
Thanks.
Part 1.
I recommend to get rid of the "link" type here - it's good for SQL world, but not for CouchDb.
Instead of this, it is better to utilize a benefit of Document Storage, i.e. store user groups in property "Groups" for "User"; and property "Users" for "Group".
With this approach you can set up filtered replication to process only changes of specific groups and these changes will already contain all the users of the group.
I want to notice, that I made an assumption, that number of groups for a user and number of groups is reasonable (hundreds at maximum) and doesn't change frequently.
Part 2.
You can just store ids in these properties and then use Views to "join" other data. Or I was also thinking about other approach (for my use case, but yours is similar):
1) Group contains only ids of users - no views needed.
2) You create a view of each user contacts, i.e. for each user get all users with whom he has mutual groups.
3) Replicate this view to client app.
When user opens a group, values (such as names and pics of contacts are taken from this local "dictionary").
This approach can save some traffic.
Please, let me know what do you think. Because right now I'm working on designing architecture of my solution. Thank you!)
Folks, I was wondering what is the best way to model document and/or map functions that allows me "Not Equals" queries.
For example, my documents are:
1. { name : 'George' }
2. { name : 'Carlin' }
I want to trigger a query that returns every documents where name not equals 'John'.
Note: I don't have all possible names before hand. So the parameters in query can be any random text like 'John' in my example.
In short: there is no easy solution.
You have four options:
sending a multi range query
filter the view response with a server-side list function
using a CouchDB plugin
use the mango query language
sending a multi range query
You can request the view with two ranges defined by startkey and endkey. You have to choose the range so, that the key John is not requested.
Unfortunately you have to find the commit request that somewhere exists and compile your CouchDB with it. Its not included in the official source.
filter the view response with a server-side list function
Its not recommended but you can use a list function and ignore the row with the key John in your response. Its like you will do it with a JavaScript array.
using a CouchDB plugin
Create an additional index with e.g. couchdb-lucene. The lucene server has such query capabilities.
use the "mango" query language
Its included in the CouchDB 2.0 developer preview. Not ready for production but will be definitely included in the stable release.
How to find particular json document details from couchdb
For ex : Database name : employee_mgmt, in that database contains 50 json documents. So i want to find particular employee json documents ( Find by employee id ).
CouchDB does in it self not provide you with collections/buckets, hence all your documents are peers. It's up to you to provide meta-data e.g. by having a property $doctype with a value representing what kind of document it is. This is useful if you are writing maps and e.g. want to create a view (secondary index) returning something applicable only to employees.
Know, if you just want to query by _id you don't need the above. Just do a simple GET with an URI as: http://host:port/databasename/documentid
More information: http://docs.couchdb.org/en/1.6.1/api/document/common.html#get--db-docid
If you want to get a batch of documents matching many _id use the builtin index _all_docs http://docs.couchdb.org/en/1.6.1/api/database/bulk-api.html#post--db-_all_docs
I'm playing with DocumentDB's client side javascript API. I want to be able to query a collection. I'd like to use a collection URL, something like:
"https://mydocumentdb.documents.azure.com:9443/dbs/my_db/colls/my_users"
but there appears to be no API function for me to query a documentdb collection without first having the database "self link" and then in turn getting the collections "self link". The only way to get these self links appears to be to first iterate through all my DB's and then pull the right self link, then iterate through my collections, get the collection, finally, use my self link that I got from the service to query the collection.
Really???
Not exactly.
You're correct in that you have to query for a collection's self-link prior to querying the collection. (I know... this can be quite annoying, and is being looked in to by the DocDB team).
However, there is no need to iterate through all of your DB/collections to retrieve self-links as they are indexed server-side.
It is better to query directly for the particular DB/collection you're looking for, which looks something like: client.queryCollections(database._self, 'SELECT * FROM collections c WHERE c.id="' + collectionId + '"'), where collectionId is an identifier you assign.
I've never worked with a database before, but I chose Couch DB because I needed a Json database, and HTTP queries seemed kinda simple. However the documentation assumes a level of knowledge I just don't have.
Assuming I have a database called 'subjects', it seems I can access the json by using GET on
http://localhost:5984/subjects/c6604f65029f1a6a5d565da029001f4c
However beyond that I'm stuck. Ideally I want to be able to:
Access a list of all the keys in the database (not their values)
Access an individual element by its key
Do I need to use views for this? Or can I just set fields in my GET request? Can someone give me a complete example of the request they'd use? Please don't link to the CouchDB documentation, it really hasn't helped me so far.
Views can be used to fetch the data
1) In order to get all keys from the database you can use below view
function(doc) {
if (doc.type=="article")
emit(doc._id,null); //emit(key,value), if you have any other field as key then specify as doc.key e.g doc.
}
You can access this view from browser using below URL
http://<ipaddress>:<port>/databasename/_design/designdocumentname/_view/viewname
e.g :
http://<ipaddress>:<port>/article/_design/articlelist/_view/articlelist
article is the database name,articlelist is name of the design document as well as view.
2) In order to access individual document by key
Below view will return all the articles belonging to a particular department
function(doc) {
if(doc.type == 'article' ) {
emit([doc.departmentname], doc);
}
}
Query this view based on the "department name"
e.g: Get all the articles belonging to "IBU3" department
http://<ipaddress>:<port>/department/_design/categoryname/_view/categoryname?key=[%22IBU3%22]