I'am having this schema:
type Invoice {
id: ID! #unique
description: String
charge: Charge
}
type Charge {
id: ID! #unique
amount: Float
dataFromAPI: DataFromAPI
}
type DataFromAPI {
id: ID! #unique
status: String
}
in the Query Resolver, I have:
async function charge(parent, args, ctx, info) {
chargeData = await ctx.db.query.charge(args, info)
chargeData.dataFromAPI = await DO_THE_API_CALL_TO_RETRIEVE_DATA()
return chargeData
}
and
async function invoice(parent, args, ctx, info) {
invoiceData = await ctx.db.query.invoice(args, info)
return invoiceData
}
the query:
query ChargeQuery {
charge {
id
amount
dataFromAPI
}
}
will return
{
charge {
id: '232323'
amount: 323
dataFromAPI: 'GREAT! DATA IS FROM API'
}
}
but this query:
query InvoiceQuery {
invoice {
id
description
charge {
id
amount
dataFromAPI
}
}
}
will return
{
Invoice {
id: '7723423',
description:'yeah',
charge {
id: '232323'
amount: 323
dataFromAPI: null
}
}
}
dataFromAPI is null because I have not called the API in this resolver.
Where should I call the function DO_THE_API_CALL_TO_RETRIEVE_DATA().
In every resolvers? I guess it is not scalable to do that.
The solution is:
We should use a resolver on the field level.
schema.graphql
type Charge {
id: ID!
invoice: Invoice!
messageErrorPayment: String
stripeChargeId: String!
dateErrorPayment: DateTime
createdAt: DateTime!
chargeData: ChargeData
}
/resolvers/index.js
const { Query } = require('./Query')
const { Mutation } = require('./mutation/Mutation')
const { Charge } = require('./Charge')
module.exports = {
Query,
Mutation,
Charge,
}
charge.js
async function chargeData(parent, args, ctx, info) {
return {
dataFromAPI: await DO_THE_API_CALL_TO_RETRIEVE_DATA()
}
}
const Charge = {
chargeData,
}
module.exports = {
Charge,
}
source: https://www.prisma.io/forum/t/how-to-use-field-resolvers-to-get-aggregates-of-inner-relation-types/2930/2?u=alan345
Related
we are currently studying the stack: cdk, appsync and amplify to migrate our applications.
In our initial tests, we were able to upload a graphql api with only appsync wit relationships and it was very smooth, nice and fast.
When testing to build with cdk, we are having difficulties to create the relationships.
Here my code:
Schema
type Person {
id: ID!
name: String!
}
input PersonInput {
id: ID!
name: String!
}
input UpdatePersonInput {
id: ID!
name: String
}
type Client {
id: ID!
type: String!
personId: String
# Person: PersonConnection
Person: Person #connection(fields: ["personId"])
}
input ClientInput {
id: ID!
type: String!
personId: String!
}
input UpdateClientInput {
id: ID!
type: String
personId: String
}
My function
const AWS = require('aws-sdk');
const docClient = new AWS.DynamoDB.DocumentClient();
async function list() {
const params = {
TableName: process.env.CLIENT_TABLE,
}
try {
const data = await docClient.scan(params).promise()
return data.Items
} catch (err) {
console.log('DynamoDB error: ', err)
return null
}
}
export default list;
My table
const clientTable = new dynamodb.Table(scope, 'ClientTable', {
billingMode: dynamodb.BillingMode.PAY_PER_REQUEST,
partitionKey: {
name: 'id',
type: dynamodb.AttributeType.STRING,
},
});
clientTable.addGlobalSecondaryIndex({
indexName: 'client-by-person-id',
partitionKey: {
name: 'personId',
type: dynamodb.AttributeType.STRING
},
sortKey: {
name: 'createdAt',
type: dynamodb.AttributeType.STRING
}
})
My query
query MyQuery {
listClients {
id
personId
type
Person {
name
}
}
}
However, my return to Person connection is null
"listClients": [
{
"id": "1",
"personId": "1",
"type": "PJ",
"Person": null
}
]
I would appreciate it if could point out our mistake
Solution of the problem based on the response of the Thorsten.
First, add resolver to the Person field in Client
export const clientResolvers = [{ typeName: "Client", fieldName: "Person" },...]
clientResolvers.map(((resolver: clientTypeResolver) => dataSource2.createResolver(resolver)))
Map function to the Person field in its lambda function
type AppSyncEvent = {
...
source: {personId: string,}
...
}
exports.handler = async (event:AppSyncEvent) => {
switch (event.info.fieldName) {
...
case "Person":
return await getPerson(event.source.personId);
}
}```
Function to solve the person field
async function getPerson(personId: string) {
console.log("CONTEXT\n" + JSON.stringify(personId, null, 2))
// console.log(context.source)
const params = {
TableName: process.env.PERSON_TABLE,
Key: { id: personId }
}
try {
const { Item } = await docClient.get(params).promise()
console.log("DATA\n" + JSON.stringify(Item, null, 2))
return Item
} catch (err) {
console.log('DynamoDB error: ', err)
}
I am new to GraphQL. I have a query which updates a user by his Id. I want to return the id of the document that was updated, but it is returning:
{
"data": {
"editUser": {
"_id": null
}
}
}
GraphQL Query:
mutation {editUser(_id: "5eb801eef0171040044de79f", name: "dd", title:"teacher" , email:"dd#here.com") {
_id
}
}
shema:
const { buildSchema } = require("graphql");
const schema = buildSchema(`type Query {
getUser(_id: ID): User
getUsers: [User]
}
type User {
_id: ID
name: String
title: String
email: String
}
type Mutation {
addUser(name: String, title: String, email: String): User,
editUser(_id: ID, name: String, title: String, email: String): User,
deleteUser(_id: ID): String
}`);
module.exports = { schema };
in resolver.js:
try {
const client = await MongoClient.connect(url);
var dbo = client.db("UserApp");
const myquery = { _id: ObjectId(args._id) };
const updateduser = await dbo
.collection("users")
.updateOne(myquery, { $set: { name: args.name } });
const founduser = await dbo.collection("users").findOne(myquery);
console.log(founduser);
return founduser._id.toString();
} catch (err) {
console.log(err);
}
As a newbie to GraphQL I would appreciate some help in the following:
I have query which retrieves its author and that author's books. I would like the author's books to be author's other books, meaning - except the one being queried. What does it involve?
apollo-angular query:
const getBookQuery = gql`
query($id: ID){
book(id: $id){
id
name
year
author {
id
firstName
lastName
books { # <-- give me all _except_ the one with $id
name
year
id
}
}
}
}
`;
and in the schema.js (node.js server) I have something like:
const RootQuery = new GraphQLObjectType({
name: 'RootQueryType',
fields: {
book: {
type: BookType,
args: { id: { type: GraphQLID } },
resolve(parent, args) {
const { id } = args;
return Book.findById(id);
},
},
books: {
type: GraphQLList(BookType),
resolve() {
return Book.find({});
},
},
// ... other queries ...
}
})
The solution I am looking for should, obviously, not break other queries for books.
You should be able to achieve the exclusion by adding an argument to the Author type def and then appropriately using that argument in the resolver for books (which should be nested resolver on your Author type). Will need to adapt syntax for apollo-angular.
type Author {
id:
firstName: String
lastName: String
books(exclude: ID): [Book]
}
const resolverMap = {
Query: {
book(arent, args, ctx, info) {
...
}
},
Author: {
books(obj, args, ctx, info) {
// Use args.exclude passed to filter results
},
},
};
const getBookQuery = gql`
query($id: ID){
book(id: $id){
id
name
year
author {
id
firstName
lastName
books(exclude: $id) {
name
year
id
}
}
}
}
`;
I have the following datamodel:
type Tvshow {
id: ID! #unique
title: String!
pricing: [Pricing]
startDate: DateTime!
endDate: DateTime!
subscribers: [Tvshowsubscription!]
.....
}
type FavoriteTvshow {
id: ID! #unique
tvshow: Tvshow!
user: User!
}
type User {
id: ID! #unique
name: String
email: String! #unique
password: String
googleID: String #unique
resetToken: String
resetTokenExpiry: String
permissions: [Permission]
address: Address
phone: String
favorites: [FavoriteTvshow!]
tvshowSubscriptions: [Tvshowsubscription!]
}
I have my custom Tvshow resolver using addFragmentToInfo:
resolver-queries.js
const Query = {
...
favoriteTvshows: forwardTo('db'),
tvshow: (parent, args, ctx, info) => {
const fragment = `fragment EnsureComputedFields on Tvshow { pricing { minQuantity maxQuantity unitPrice} subscribers { id }}`
return ctx.db.query.tvshow({}, addFragmentToInfo(info, fragment))
},
....
};
tvshow-resolver.js
const Tvshow = {
countSubscribers: (parent) => {
return parent.subscribers.length;
},
}
This is an example, I have more computed fields for Tvshow
I can query Tvshows with countSubscribers, It works fine doing something like this:
query SINGLE_TVSHOW_QUERY($id: ID!) {
tvshow(where: { id: $id }) {
id
title
pricing {
minQuantity
maxQuantity
unitPrice
}
startDate
endDate
countSubscribers
}
}
But what I want to do is to get all the favorite Tvshows from an user returning the countSubscribers, a query for that could be something like this:
query FAVORITES_FROM_USER($userId: ID!) {
favoriteTvshows(where: { user: {id: $userId} }) {
tvshow {
id
title
startDate
endDate
countSubscribers
}
}
}
The problem is that when I query this, in the tvshow-resolver.js I mentioned before, the parent doesn’t have any subscribers object
The error was very silly but I will post it anyway. I needed subscribers in the query
query FAVORITES_FROM_USER($userId: ID!) {
favoriteTvshows(where: { user: {id: $userId} }) {
tvshow {
id
title
startDate
endDate
subscribers { <---
id
quantity
}
countSubscribers
}
}
}
That way the parent in tvshow-resolver.js will have subscribers object
I'm trying to return a subscription which consists of the following:
const postsSubscription = gql`
subscription postAdded {
postAdded {
id
title
description
author{
name
}
}
}
`
What happens is that Author is type of User, and I just pass an authorId. That means that I don't have the author name when I create the Post:
createPost: async (root, req, { posts }) => {
const Item = {
id: uuid.v4(),
authorId: '565dbdc0-36f2-4bba-be67-c126d0c71fff',
...req
}
await posts.create({ Item })
pubsub.publish('postAdded', { postAdded: Item })
return Item
},
Here is the Author resolver:
Post: {
author: async({ authorId }, req, { users }) => {
const Key = { id: authorId }
const { Item } = await users.get({ Key })
return Item
}
}
Here is the schema:
type Post {
id: ID
title: String
description: String
author: User #relation(name: "PostAuthor")
}
type User {
id: ID
name: String
email: String
password: String
posts: [Post] #relation(name: "UserPosts")
}
type PostPayload {
post: Post
}
type CreateUserPayload {
user: User
}
type Query {
allPosts: [Post]
allUsers: [User]
post(id: ID!): Post
user(id: ID!): User
}
type Mutation {
createPost(input: CreatePostInput!): PostPayload
updatePost(input : UpdatePostInput!): PostPayload
createUser(input : CreateUserInput!): CreateUserPayload
}
type Subscription {
postAdded: Post
}
input CreatePostInput {
title: String!
description: String!
}
input UpdatePostInput {
id: ID!
title: String!,
description: String!
}
input CreateUserInput {
name: String!
email: String!
password: String!
}
schema {
query: Query
mutation: Mutation
subscription: Subscription
}
So, my question is, how to pass all required fields (including the connections) to the subscription?
I made it work, but not as I wanted.
1) I had to remove this part of the code:
Post: {
author: async({ authorId }, req, { users }) => {
const Key = { id: authorId }
const { Item } = await users.get({ Key })
return Item
}
}
and added this function to the createPost function itself:
createPost: async (root, { input }, { posts, users }) => {
const Key = { id: '3b1884b8-9ee7-4d9d-ab2f-ff32bcd69b9a' }
const user = await users.get({ Key })
const Item = {
id: uuid.v4(),
author: user.Item,
...input
}
await posts.create({ Item })
await pubsub.publish(POST_ADDED_TOPIC, { [POST_ADDED_TOPIC]: Item })
return { post: Item }
}
So this is kinda fixed. But, if you know how to fix this, using the first approach (Post: author thingy) I'll appreciate.