Referenced objects in DB returning null in GraphQL Query - mongodb

Question

I have the following database model:
Each Mediablock contains a reference to exactly one UTS object and one Media object.
Each UTS object contains rawText and normalisedText
Each Media object contains a url and a timestamp
My schema.prisma looks like this:
datasource db {
provider = "mongodb"
url = env("DATABASE_URL")
}
generator client {
provider = "prisma-client-js"
}
model Mediablock {
id String #id #default(auto()) #map("_id") #db.ObjectId // gen a new, unique id
UTS UTS #relation(fields: [utsId], references: [id])
utsId String #unique #map("uts_id") #db.ObjectId
Media Media #relation(fields: [mediaId], references: [id])
mediaId String #unique #map("media_id") #db.ObjectId
}
model UTS {
id String #id #default(auto()) #map("_id") #db.ObjectId
rawText String
normalisedText String
createdAt DateTime #default(now())
Mediablock Mediablock?
}
// // Mediablocks contain a Video object and connect back to the Mediablock.
// // mediablockId must have #db.ObjectId to match up with Mediablock's id type
model Media {
id String #id #default(auto()) #map("_id") #db.ObjectId
url String
createdAt DateTime #default(now())
Mediablock Mediablock?
}
My resolvers look like this:
const { PrismaClient } = require('#prisma/client');
const prisma = new PrismaClient();
//This resolver retrieves mediabooks from the "mediabooks" array above.
module.exports = {
Query: {
allMediablocks: () => prisma.mediablock.findMany(),
allMedia: () => prisma.media.findMany(),
allUTS: () => prisma.uts.findMany(),
},
};
And my typedefs looks like this:
module.exports = `
type Mediablock {
id: ID!
uts: UTS
media: Media # can be null when the text is generated first
}
type UTS {
id: ID!
rawText: String!
normalisedText: String!
}
type Media {
id: ID!
url: String!
createdAt: String!
}
# The "Query" type is special: it lists all of the available queries that
# clients can execute, along with the return type for each. In this
# case, the "allMediablocks" query returns an array of zero or more Mediablocks (defined above).
type Query {
allMediablocks: [Mediablock]
allMedia: [Media]
allUTS: [UTS]
}
`;
My seed file looks like this:
const { PrismaClient } = require('#prisma/client');
const prisma = new PrismaClient();
const mediaData = [
{
UTS: {
create: {
rawText: 'Welcome',
normalisedText: 'welcome',
},
},
Media: {
create: {
url: 'https://www.youtube.com/watch?v=kq9aShH2Kg4',
createdAt: '2022-09-29T12:00:00.000Z',
}
}
}
];
async function main() {
console.log(`Started seeding ...`);
for (const d of mediaData) {
const mediablock = await prisma.Mediablock.create({
data: d,
});
console.log(`Created Mediablock with id: ${mediablock.id}`);
}
console.log(`\nSeeding complete.`);
}
main()
.then(async () => {
await prisma.$disconnect();
})
.catch(async (e) => {
console.error(e);
await prisma.$disconnect();
process.exit(1);
});
My problem is that when I attempt to query allMediablocks, I can't get any of the UTS or Media data.
query allMediaBlocks {
allMediablocks {
uts {
normalisedText
}
media {
url
}
}
}
// response
{
"data": {
"allMediablocks": [
{
"uts": null,
"media": null
}
]
}
}
I just get null values for both, when in fact, the database (MongoDB) contains references to both of these objects in other tables.
What am I doing wrong? Are my resolvers incorrect?
Is my schema structured incorrectly for MongoDB?

Answer 1

I've fixed it by changing my schema.prisma to be:
datasource db {
provider = "mongodb"
url = env("DATABASE_URL")
}
generator client {
provider = "prisma-client-js"
}
model Mediablock {
id String #id #default(auto()) #map("_id") #db.ObjectId // gen a new, unique id
utsId String #unique #map("uts_id") #db.ObjectId
uts UTS #relation(fields: [utsId], references: [id])
mediaId String #unique #map("media_id") #db.ObjectId
media Media #relation(fields: [mediaId], references: [id])
}
model UTS {
id String #id #default(auto()) #map("_id") #db.ObjectId
rawText String
normalisedText String
createdAt DateTime #default(now())
mediablock Mediablock?
}
// // Mediablocks contain a Video object and connect back to the Mediablock.
// // mediablockId must have #db.ObjectId to match up with Mediablock's id type
model Media {
id String #id #default(auto()) #map("_id") #db.ObjectId
url String
createdAt DateTime #default(now())
mediablock Mediablock?
}
My resolver to be:
const { PrismaClient } = require('#prisma/client');
const prisma = new PrismaClient();
//This resolver retrieves mediabooks from the "mediabooks" array above.
module.exports = {
Query: {
allMediablocks: () => prisma.mediablock.findMany({
include: {
media: true,
uts: true
}
}),
allMedia: () => prisma.media.findMany(),
allUTS: () => prisma.uts.findMany(),
},
};
And my typedefs to be:
module.exports = `
type Mediablock {
id: ID!
uts: UTS
media: Media # can be null when the text is generated first
}
type UTS {
id: ID!
rawText: String!
normalisedText: String!
}
type Media {
id: ID!
url: String!
createdAt: String!
}
# The "Query" type is special: it lists all of the available queries that
# clients can execute, along with the return type for each. In this
# case, the "allMediablocks" query returns an array of zero or more Mediablocks (defined above).
type Query {
allMediablocks: [Mediablock]
allMedia: [Media]
allUTS: [UTS]
}
`;
I also changed the way my seed function works:
const { PrismaClient } = require('#prisma/client');
const prisma = new PrismaClient();
const mediaData = [
{
uts: {
create: {
rawText: 'Welcome',
normalisedText: 'welcome',
createdAt: '2022-09-29T12:00:00.000Z',
},
},
media: {
create: {
url: 'https://www.youtube.com/watch?v=kq9aShH2Kg4',
createdAt: '2022-09-29T12:00:00.000Z',
}
}
}
];
async function main() {
console.log(`Started seeding ...`);
for (const d of mediaData) {
const mediablock = await prisma.Mediablock.create({
data: d,
});
console.log(mediablock);
}
console.log(`\nSeeding complete.`);
}
main()
.then(async () => {
await prisma.$disconnect();
})
.catch(async (e) => {
console.error(e);
await prisma.$disconnect();
process.exit(1);
});
Now, using the same GraphQL query:
query allMediaBlocks {
allMediablocks {
uts {
normalisedText
}
media {
url
}
}
}
I get the following (desired) response:
{
"data": {
"allMediablocks": [
{
"uts": {
"normalisedText": "welcome"
},
"media": {
"url": "https://www.youtube.com/watch?v=kq9aShH2Kg4"
}
}
]
}
}