I am trying to append extra fields to the info object when querying data from prisma database. I have seen this post but I can't get fragments working.
I have below migrations:
type User {
id: ID! #unique
name: String
}
type Video {
id: ID! #unique
name: String
likes: [Like]
}
type Like {
id: ID! #unique
user: User
createdAt: DateTime!
}
Now, I would like to query all videos and check if current user has already liked a video. If so, the likes object should read the createdAt value, otherwise it would be empty.
I am doing this in playground via following query:
query {
videos() {
id
name
hasVoted: likes(where: {user: {id: "cjr7r85jy00rc0892dfwpu96u"}){
createdAt
}
}
}
this works but I would like to add the hasVoted to my query resolver to automatically append it to all queries. How can I do this ?
I tried solving it via fragments but without luck:
videos: {
fragment: `fragment hasVoted on Video {
hasVoted: likes (where: {user: {id: "cjr7r85jy00rc0892dfwpu96u"}}){
createdAt
}
}`,
resolve: async (_, args, ctx, info) => {
return await ctx.prisma.query.videos({},info);
}
}
Anyone has some ideas how I can do this? thx!
You can use addFragmentToInfo from graphql-bindings
https://oss.prisma.io/content/graphql-binding/02-api-reference#addfragmenttoinfo
Related
I have begun testing out prisma 2 and graphql in general for a new application. I am running into an issue with an explicit many to many table on being able to query relations.
Here is my apollo schema:
scalar DateTime
type Query {
user(id: String!): User
users: [User]
spaces: [Space]
roles: [Role]
}
type Mutation {
createUser(id: String!, email: String!): User!
createSpace(name: String!): Space!
}
type User {
id: ID!
email: String!
spaces: [UserSpace!]
createdAt: DateTime!
updatedAt: DateTime!
}
type Space {
id: ID!
name: String!
users: [UserSpace!]
createdAt: DateTime!
updatedAt: DateTime!
}
type Role {
id: ID!
name: String!
description: String!
users: UserSpace
createdAt: DateTime!
updatedAt: DateTime!
}
type UserSpace {
id: ID!
user: User!
space: Space!
role: Role!
createdAt: DateTime!
updatedAt: DateTime!
}
Here is my prisma schema:
// This is your Prisma schema file,
// learn more about it in the docs: https://pris.ly/d/prisma-schema
// npx prisma migrate dev
// npx prisma generate
datasource db {
provider = "postgresql"
url = env("DATABASE_URL")
}
generator client {
provider = "prisma-client-js"
}
model User {
id String #id
email String #unique
spaces UserSpace[]
createdAt DateTime #default(now())
updatedAt DateTime #updatedAt
}
model Space {
id Int #default(autoincrement()) #id
name String #unique
users UserSpace[]
createdAt DateTime #default(now())
updatedAt DateTime #updatedAt
}
model Role {
id Int #default(autoincrement()) #id
name String #unique
description String
users UserSpace[]
createdAt DateTime #default(now())
updatedAt DateTime #updatedAt
}
model UserSpace {
id Int #default(autoincrement()) #id
user User #relation(fields: [userId], references: [id])
userId String
space Space #relation(fields: [spaceId], references: [id])
spaceId Int
role Role #relation(fields: [roleId], references: [id])
roleId Int
createdAt DateTime #default(now())
updatedAt DateTime #updatedAt
}
Here is my mutations resolver:
const { prisma } = require(".prisma/client");
async function createUser(parent, args, context, info) {
return await context.prisma.user.create({
data: {
...args,
},
});
}
async function createSpace(parent, args, context, info) {
const isAuthenticated = context.authentication.isAuthenticated;
let role = null;
if(!isAuthenticated) {
throw new Error("Not Authenticated");
}
try {
role = await context.prisma.role.findUnique({
where: {
name: "Space Administrator",
},
});
}
catch(err) {
throw new Error(err);
}
return await context.prisma.space.create({
data: {
...args,
users: {
create: {
role: {
connect: { id: role.id },
},
user: {
connect: { id: context.authentication.auth0Id },
},
},
},
},
});
}
module.exports = {
createUser,
createSpace,
}
Here is my user resolver (I know this is where the problem is however I do not know how to solve the issue):
function spaces(parent, args, context, info) {
return context.prisma.user.findUnique({ where: { id: parent.id } }).spaces();
}
module.exports = {
spaces,
}
Basically when I create the space the user is added as a Space Administrator to the space and then should be able to be queried with the following:
query {
users {
id
email
spaces {
id
role {
name
}
space {
name
}
}
createdAt
}
}
However when I run the query I get the following error:
"message": "Cannot return null for non-nullable field UserSpace.role.",
How in prisma 2 do I make the resolver for the users work with an explicit many to many table and how it has the third relation in there? I am new to prisma and graphql so if there anything else that stands out also I would like to have the input.
I'm using the word type to refer to object-models in your GraphQL schema and model to refer to data-models in your Prisma Schema.
The Problem
I see that you have a User type resolver, that has a resolver function for User.spaces field in your User type. The query that you have defined in your User.spaces resolver will return the relevant userSpace records from the database.
However, these userSpace records do not by default resolve the role field, as it is a relation field. This is how prisma works (relation fields are not resolved by default, unless explicitly stated).
Solution
Create a resolver for the UserSpace type and explicitly define the the resolver function for UserSpace.role field. This is what it will look like
// UserSpace resolver module
function role(parent, args, context, info) {
return context.prisma.userSpace.findUnique({ where: { id: parent.id } }).role();
}
module.exports = {
role,
}
While there are some other ways to solve this problem, the way I have shown (along with the specific syntax) is recommended because under the hood it allows prisma to perform certain optimizations to solve the n+1 query problem. But, if you don't know what that is, you don't necessarily need to worry about it either.
Did you provide the value to users arg? like this: users(id: "string_value"). Because is id is required.
From GraphQL Client's perspective, how do I perform a query with multiple nested resolvers where the fields from the parent are passed as arguments to the child resolver?
Here is a minimal example:
GraphQL Schema:
type Author {
id: ID!
name: String!
}
type Book {
id: ID!
title: String!
releaseDate: String!
}
type Query {
// Returns a list of Authors ordered by name, 'first' indicates how many entries to return
getAllAuthors(first: Int!): [Author]!
// Returns a list of Books ordered by releaseDate, 'first' indicates how many entries to return
getBooksByAuthorId(first: Int! authorId: ID!): [Book]!
}
Is it possible to write a query to get all authors and their last released book? Something around the lines:
query GetAuthorsWithLastBook($first: Int!) {
getAllAuthors(first: $first) {
authorId: id
name
lastBook: getBooksByAuthor(1, authorId) {
title
}
}
}
In the example above, I attempted to alias getAllAuthors.id as authorId and pass the alias down as argument to getBooksByAuthor(...) but that didn't work.
The key aspect of the problem is that I don't know the authorIds beforehand. I could fetch the authors first and build a query to fetch their last book but that will result in multiple queries and that is something I would like to avoid.
Update
A Java Kickstarter example is available here: https://www.graphql-java-kickstart.com/tools/schema-definition/
yes, on the graphql definition, you need to add lastBook in the Author
type Author {
id: ID!
name: String!
lastBook: [Book]
}
Next up u need to write the resolver for the lastBook
const resolvers = {
Query: {
Author {
lastBook: (parent, args) {
const userId = parent.id;
return getBooksByAuthor(userId, 1);
},
}
}
};
Within my resolver I seem to be unable to fetch connected data
this works in the graphql playground (prisma) but I am unsure of the syntax about how to form a resolver in apollo server
// my typedef for activity is
type Activity {
id: ID! #id
ActivityType: ActivityType!
title: String!
date: DateTime
user: User!
distance: Float!
distance_unit: Unit!
duration: Float!
elevation: Float
elevation_unit: Unit
createdAt: DateTime! #createdAt
updatedAt: DateTime! #updatedAt
// and my resolver currently looks like this
async activity(parent, args, ctx, info) {
const foundActivity = await ctx.db.query.activity({
where: {
id: args.id
}
});
// todo fetch user data from query
console.log(foundActivity);
}
// where db has been placed onto the ctx (context)
// the CL gives all of the data for Activity apart from the user
// in the playground I would do something like this
query activity {
activity(where: {
id: "cjxxow7c8si4o0b5314f9ibek"
}){
title
user {
id
name
}
}
}
// but I do not know how to specify what is returned in my resolver.
console.log(foundActivity) gives:
{ id: 'cjxxpuh1bsq750b53psd2c77d',
ActivityType: 'CYCLING',
title: 'Test Activity',
date: '2019-07-10T20:21:27.681Z',
distance: 13.4,
distance_unit: 'KM',
duration: 90030,
elevation: 930,
elevation_unit: 'METERS',
createdAt: '2019-07-10T20:48:50.879Z',
updatedAt: '2019-07-10T20:48:50.879Z' }
Prisma is the DB ORM and then I have an Apollo-Server 2 server running on top of that. Unfortunately, stack overflow also thinks that there is too much code on this post so I will have to waffle on about inconsequential gibberish due to the fact that their system can't handle it.
You will have to implement a resolver for Activity.user. Unfortunately your entity does not seem to contain a reference to the user. First, add the user connection to your Prisma data model. Then implement a resolver for Activity.user. I am not very familiar with Prisma 1 but this naive implementation should already do what you want:
let resolvers = {
Query: {
// ...
},
Activity: {
user(parent, args, ctx) {
return ctx.db.query.activity({ id: parent.id }).user();
}
}
}
Find out more about resolving relations in Prisma here
So the answer was incredibly simple:
I just add a second argument to the query (after the "where" with a gql tag of the data shape to be returned so my code now looks like:
const foundActivity = await ctx.db.query.activity(
{
where: {
id: args.id
}
},
`{id title user { id name }}`
);
Let's take an example from the github repo of prisma:
We have a user, the user could have multiple posts, and one post could have multiple links.
My goal is, to retrieve all posts and all links.
This means, my response is a list (links) in a list (posts).
I want to map the values I get back as two nested lists.
datamodel.prisma
type User {
id: ID! #id
email: String! #unique
name: String
posts: [Post]!
}
type Post {
id: ID! #id
createdAt: DateTime! #createdAt
updatedAt: DateTime! #updatedAt
published: Boolean! #default(value: false)
title: String!
content: String
author: User!
links: [Link]!
}
type Link {
id: ID! #id
url: String
title: String
post: Post!
}
schema.graphql
type Query {
...
}
type Mutation {
...
}
type Link {
id: ID!
url: String
title: String
post: Post!
}
type Post {
id: ID!
createdAt: DateTime!
updatedAt: DateTime!
published: Boolean!
title: String!
content: String
author: User!
}
type User {
id: ID!
email: String!
name: String
posts: [Post]!
}
I want to query all posts of a user, and all of the links for every post in the response.
How would I query this request?
user {
id
posts {
id
links {
id
}
}
}
The above code snipper would not work.
EDIT
I want to use the following:
User: {
listPosts: (parent, args, context, info) {
return context.prisma.posts().links()
}
}
So in my response (data in front-end via react-apollo Query Component), I want to map over posts AND the links in each post.
BUT the links attribute in posts is null.
Is there another way to achieve this?!
According to the docs:
Prisma client has a fluent API to query relations in your database. Meaning you can simply chain your method calls to navigate the relation properties of the returned records. This is only possible when retrieving single records, not for lists. Meaning you can not query relation fields of records that are returned in a list.
In order to get around that limitation, you can use the $fragment method:
const fragment = `
fragment UserWithPostsAndLinks on User {
id
email
name
posts {
id
title
content
links {
id
url
title
}
}
}
`
const userWithPostsAndLinks = await prisma.user({ id: args.id }).$fragment(fragment)
Say I have the following GraphQL Schema
query {
allAuthors: [Author]
}
type Author {
id: ID!
name: String!
books: [Book]
}
type Book {
id: ID!
name: String!
author: Author!
}
Now I can successfully run the following query to get all the authors and their associated books
query {
allAuthors {
name,
books {
name
}
}
}
However, if I only want to get the first three books for all authors, how would I go about doing something like that? Can we index the books field in the Author type from within a query? If so, how?
I tried something like this and it doesn't work
query {
allAuthors {
name,
books[3] {
name
}
}
}
GraphQL doesn't have syntax for this.
You can add a "limit" parameter to a field, and this is common enough:
type Query {
allAuthors(limit: Int, offset: Int): [Author!]!
}
type Author {
id: ID!
name: String!
books(limit: Int, offset: Int): [Book!]!
}
If you add parameters like this to the schema, then the query you want (for all authors, get the first three books) could look like
{
allAuthors {
name
books(limit: 3) {
name
}
}
}