I have a model with several embedded models. I need to query for a record to see if it exists. the issue is that I will have to include reference to multiple embedded documents my query would have to include the following params:
{
"first_name"=>"Steve",
"last_name"=>"Grove",
"email_addresses"=>[
{"type"=>"other", "value"=>"steve#stevegrove.com", "primary"=>"true"}
],
"phone_numbers"=>[
{"type"=>"work_fax", "value"=>"(720) 555-0631"},
{"type"=>"home", "value"=>"(303) 555-1978"}
],
"addresses"=>[
{"type"=>"work", "street_address"=>"6390 N Main Street", "city"=>"Elbert", "state"=>"CO"}
],
}
How can I query for all the embedded docs even though some fields are missing such as _id and associations?
A few things to think about.
Are you sure the query HAS to contain all these parameters? Is there not a subset of this information that uniquely identifies the record? Say (first_name, last_name, and an email_addresses.value). It would be silly to query all the conditions if you could accomplish the same thing in less work.
In Mongoid the where criteria allows you to use straight javascript, so if you know how to write the javascript criteria you could just pass a string of javascript to where.
Else you're left writing a really awkward where criteria statement, thankfully you can use the dot notation.
Something like:
UserProfile.where(first_name: "Steve",
last_name: "Grove",
:email_addresses.matches => {type: "other",
value: "steve#stevegrove.com",
primary: "true"},
..., ...)
in response to the request for embedded js:
query = %{
function () {
var email_match = false;
for(var i = 0; i < this.email_addresses.length && !email_match; i++){
email_match = this.email_addresses[i].value === "steve#stevegrove.com";
}
return this.first_name === "Steve" &&
this.last_name === "Grove" &&
email_match;
}
}
UserProfile.where(query).first
It's not pretty, but it works
With Mongoid 3 you could use elem_match http://mongoid.org/en/origin/docs/selection.html#symbol
UserProfile.where(:email_addresses.elem_match => {value: 'steve#stevegrove.com', primary: true})
This assumes
class UserProfile
include Mongoid::Document
embeds_many :email_addresses
end
Now if you needed to include every one of these fields, I would recommend using the UserProfile.collection.aggregate(query). In this case you could build a giant hash with all the fields.
query = { '$match' => {
'$or' => [
{:email_addresses.elem_match => {value: 'steve#stevegrove.com', primary: true}}
]
} }
it starts to get a little crazy, but hopefully that will give you some insight into what your options might be. https://coderwall.com/p/dtvvha for another example.
Related
Assume you have a GraphQL type and it includes many fields.
How to query all the fields without writing down a long query that includes the names of all the fields?
For example, If I have these fields :
public function fields()
{
return [
'id' => [
'type' => Type::nonNull(Type::string()),
'description' => 'The id of the user'
],
'username' => [
'type' => Type::string(),
'description' => 'The email of user'
],
'count' => [
'type' => Type::int(),
'description' => 'login count for the user'
]
];
}
To query all the fields usually the query is something like this:
FetchUsers{users(id:"2"){id,username,count}}
But I want a way to have the same results without writing all the fields, something like this:
FetchUsers{users(id:"2"){*}}
//or
FetchUsers{users(id:"2")}
Is there a way to do this in GraphQL ??
I'm using Folkloreatelier/laravel-graphql library.
Unfortunately what you'd like to do is not possible. GraphQL requires you to be explicit about specifying which fields you would like returned from your query.
Yes, you can do this using introspection. Make a GraphQL query like (for type UserType)
{
__type(name:"UserType") {
fields {
name
description
}
}
}
and you'll get a response like (actual field names will depend on your actual schema/type definition)
{
"data": {
"__type": {
"fields": [
{
"name": "id",
"description": ""
},
{
"name": "username",
"description": "Required. 150 characters or fewer. Letters, digits, and #/./+/-/_ only."
},
{
"name": "firstName",
"description": ""
},
{
"name": "lastName",
"description": ""
},
{
"name": "email",
"description": ""
},
( etc. etc. ...)
]
}
}
}
You can then read this list of fields in your client and dynamically build a second GraphQL query to get the values of these fields.
This relies on you knowing the name of the type that you want to get the fields for -- if you don't know the type, you could get all the types and fields together using introspection like
{
__schema {
types {
name
fields {
name
description
}
}
}
}
NOTE: This is the over-the-wire GraphQL data -- you're on your own to figure out how to read and write with your actual client. Your GraphQL javascript library may already employ introspection in some capacity. For example, the apollo codegen command uses introspection to generate types.
2022 Update
Since this answer was originally written, it is now a recommended security practice to TURN OFF introspection in production. Reference: Why you should disable GraphQL introspection in production.
For an environment where introspection is off in production, you could use it in development as a way to assist in creating a static query that was used in production; you wouldn't actually be able to create a query dynamically in production.
I guess the only way to do this is by utilizing reusable fragments:
fragment UserFragment on Users {
id
username
count
}
FetchUsers {
users(id: "2") {
...UserFragment
}
}
I faced this same issue when I needed to load location data that I had serialized into the database from the google places API. Generally I would want the whole thing so it works with maps but I didn't want to have to specify all of the fields every time.
I was working in Ruby so I can't give you the PHP implementation but the principle should be the same.
I defined a custom scalar type called JSON which just returns a literal JSON object.
The ruby implementation was like so (using graphql-ruby)
module Graph
module Types
JsonType = GraphQL::ScalarType.define do
name "JSON"
coerce_input -> (x) { x }
coerce_result -> (x) { x }
end
end
end
Then I used it for our objects like so
field :location, Types::JsonType
I would use this very sparingly though, using it only where you know you always need the whole JSON object (as I did in my case). Otherwise it is defeating the object of GraphQL more generally speaking.
GraphQL query format was designed in order to allow:
Both query and result shape be exactly the same.
The server knows exactly the requested fields, thus the client downloads only essential data.
However, according to GraphQL documentation, you may create fragments in order to make selection sets more reusable:
# Only most used selection properties
fragment UserDetails on User {
id,
username
}
Then you could query all user details by:
FetchUsers {
users() {
...UserDetails
}
}
You can also add additional fields alongside your fragment:
FetchUserById($id: ID!) {
users(id: $id) {
...UserDetails
count
}
}
Package graphql-type-json supports custom-scalars type JSON.
Use it can show all the field of your json objects.
Here is the link of the example in ApolloGraphql Server.
https://www.apollographql.com/docs/apollo-server/schema/scalars-enums/#custom-scalars
Assume you have a GraphQL type and it includes many fields.
How to query all the fields without writing down a long query that includes the names of all the fields?
For example, If I have these fields :
public function fields()
{
return [
'id' => [
'type' => Type::nonNull(Type::string()),
'description' => 'The id of the user'
],
'username' => [
'type' => Type::string(),
'description' => 'The email of user'
],
'count' => [
'type' => Type::int(),
'description' => 'login count for the user'
]
];
}
To query all the fields usually the query is something like this:
FetchUsers{users(id:"2"){id,username,count}}
But I want a way to have the same results without writing all the fields, something like this:
FetchUsers{users(id:"2"){*}}
//or
FetchUsers{users(id:"2")}
Is there a way to do this in GraphQL ??
I'm using Folkloreatelier/laravel-graphql library.
Unfortunately what you'd like to do is not possible. GraphQL requires you to be explicit about specifying which fields you would like returned from your query.
Yes, you can do this using introspection. Make a GraphQL query like (for type UserType)
{
__type(name:"UserType") {
fields {
name
description
}
}
}
and you'll get a response like (actual field names will depend on your actual schema/type definition)
{
"data": {
"__type": {
"fields": [
{
"name": "id",
"description": ""
},
{
"name": "username",
"description": "Required. 150 characters or fewer. Letters, digits, and #/./+/-/_ only."
},
{
"name": "firstName",
"description": ""
},
{
"name": "lastName",
"description": ""
},
{
"name": "email",
"description": ""
},
( etc. etc. ...)
]
}
}
}
You can then read this list of fields in your client and dynamically build a second GraphQL query to get the values of these fields.
This relies on you knowing the name of the type that you want to get the fields for -- if you don't know the type, you could get all the types and fields together using introspection like
{
__schema {
types {
name
fields {
name
description
}
}
}
}
NOTE: This is the over-the-wire GraphQL data -- you're on your own to figure out how to read and write with your actual client. Your GraphQL javascript library may already employ introspection in some capacity. For example, the apollo codegen command uses introspection to generate types.
2022 Update
Since this answer was originally written, it is now a recommended security practice to TURN OFF introspection in production. Reference: Why you should disable GraphQL introspection in production.
For an environment where introspection is off in production, you could use it in development as a way to assist in creating a static query that was used in production; you wouldn't actually be able to create a query dynamically in production.
I guess the only way to do this is by utilizing reusable fragments:
fragment UserFragment on Users {
id
username
count
}
FetchUsers {
users(id: "2") {
...UserFragment
}
}
I faced this same issue when I needed to load location data that I had serialized into the database from the google places API. Generally I would want the whole thing so it works with maps but I didn't want to have to specify all of the fields every time.
I was working in Ruby so I can't give you the PHP implementation but the principle should be the same.
I defined a custom scalar type called JSON which just returns a literal JSON object.
The ruby implementation was like so (using graphql-ruby)
module Graph
module Types
JsonType = GraphQL::ScalarType.define do
name "JSON"
coerce_input -> (x) { x }
coerce_result -> (x) { x }
end
end
end
Then I used it for our objects like so
field :location, Types::JsonType
I would use this very sparingly though, using it only where you know you always need the whole JSON object (as I did in my case). Otherwise it is defeating the object of GraphQL more generally speaking.
GraphQL query format was designed in order to allow:
Both query and result shape be exactly the same.
The server knows exactly the requested fields, thus the client downloads only essential data.
However, according to GraphQL documentation, you may create fragments in order to make selection sets more reusable:
# Only most used selection properties
fragment UserDetails on User {
id,
username
}
Then you could query all user details by:
FetchUsers {
users() {
...UserDetails
}
}
You can also add additional fields alongside your fragment:
FetchUserById($id: ID!) {
users(id: $id) {
...UserDetails
count
}
}
Package graphql-type-json supports custom-scalars type JSON.
Use it can show all the field of your json objects.
Here is the link of the example in ApolloGraphql Server.
https://www.apollographql.com/docs/apollo-server/schema/scalars-enums/#custom-scalars
I am struggling to get this working efficiently I think map reduce is the answer but can't getting anything working, I know it is probably a simple answer hopefully someone can help
Entry Model looks like this:
field :var_name, type: String
field :var_data, type: String
field :var_date, type: DateTime
field :external_id, type: Integer
If the external data source malfunctions we get duplicate data. One way to stop this was when consuming the results we check if a record with the same external_id already exists, as one we have already consumed. However this is slowing down the process a lot. The plan now is to check for duplicates once a day. So we are looking get a list of Entries with the same external_id. Which we can then sort and delete those no longer needed.
I have tried adapting the snippet from here https://coderwall.com/p/96dp8g/find-duplicate-documents-in-mongoid-with-map-reduce as shown below but get
failed with error 0: "exception: assertion src/mongo/db/commands/mr.cpp:480"
def find_duplicates
map = %Q{
function() {
emit(this.external_id, 1);
}
}
reduce = %Q{
function(key, values) {
return Array.sum(values);
}
}
Entry.all.map_reduce(map, reduce).out(inline: true).each do |entry|
puts entry["_id"] if entry["value"] != 1
end
end
Am I way off? Could anyone suggest a solution? I am using Mongiod, Rails 4.1.6 and Ruby 2.1
I got it working using the suggestion in the comments of the question by Stennie using the Aggregation framework. It looks like this:
results = Entry.collection.aggregate([
{ "$group" => {
_id: { "external_id" => "$external_id"},
recordIds: {"$addToSet" => "$_id" },
count: { "$sum" => 1 }
}},
{ "$match" => {
count: { "$gt" => 1 }
}}
])
I then loop through the results and delete any unnecessary entries.
I'm a newbie on RoR (and Ruby). I need a little help about a json response (with Grape).
This is the sample:
{
events: [
{
'some data':'some data',
place_id: 1
}
]
}
Now this is the result of Events.all in Rails, but I want to make for each event a query for the place, to have more data instead only id. I'm sure that new lambda function can help me, but for now I have no idea about to make it. I'm trying without success...
Thanks in advance
UPDATE
Desired result
{
events: [
{
'some data':'some data',
place : {
id: 1,
name: 'Blablabla'
}
]
}
Consider using ActiveModelSerializers which allows you to define how your models should be serialized in a manner similar to ActiveRecord DSL (e.g. your problem would be solved by defining that event has_one :place)
:events => events.as_json(include: :place)
This is a useful for my problem. After add belongs_to, obviously.
from http://api.rubyonrails.org/classes/ActiveModel/Serializers/JSON.html
I am triying remove field in a big document, therefore I would like to do something:
collection.update({'_id' => #id}, {"$unset" => {'herField'})
But it is not possible. I don't want to rewrite entire document, any idea?
EDIT: I am using https://github.com/mongodb/mongo-ruby-driver
Your syntax looks slightly incorrect. As per docs:
collection.update( { _id: #id }, { $unset: { herField: true } }, { multi: true });
Need the 'multi' option if you want to update multiple documents. E.g. from all records on this collection.
http://docs.mongodb.org/manual/reference/operator/unset/#op._S_unset