CODEWITHSUNDEEP
postgresqltypeormapollo-servertypegraphql
Fisk
Fisk

Reputation: 247

Error retrieving data from DB using typeorm and type-graphql

I'm using type-graphql in conjunction with typeorm, apollo-server-express and postgreSQL. I have a User and a Customer entity in a 1:n relationship, meaning one user can have multiple customers.

I can create users and customers just fine, but when attempting to retrieve the user associated to a customer using Apollo Server playground, I get an error message stating "Cannot return null for non-nullable field Customer.user."

When I check the database, the associated user id on the customer table is definitely not null (see attached image).

query {
  customers {
    customerId
    customerName
    user {      
      userId    
    }         
  }
}

Does anyone know what I'm doing wrong?

enter image description here

User.ts

import { Field, ID, ObjectType } from "type-graphql";
import { BaseEntity, Column, Entity, OneToMany, PrimaryGeneratedColumn } from "typeorm";
import { Customer } from "./Customer";

@ObjectType()
@Entity("users")
export class User extends BaseEntity {
    @Field(() => ID)
    @PrimaryGeneratedColumn("uuid")
    userId: string;

    @Field()
    @Column({ unique: true })
    email: string;

    @Column({ nullable: false })
    password: string;

    @Field(() => Customer)
    @OneToMany(() => Customer, customer => customer.user)
    customers: Customer[]
}

Customer.ts

import { Field, ID, ObjectType } from "type-graphql";
import { BaseEntity, Column, Entity, ManyToOne, PrimaryGeneratedColumn } from "typeorm";
import { User } from "./User";


@ObjectType()
@Entity("customers")
export class Customer extends BaseEntity {
    @Field(() => ID)
    @PrimaryGeneratedColumn("uuid")
    customerId: string;

    @Field()
    @Column()
    customerName: string;

    @Field(() => User)
    @ManyToOne(() => User, user => user.customers)
    user: User;
}

CustomerResolver.ts

export class CustomerResolver {
    @Query(() => [Customer])
    async customers():Promise<Customer[]> {

        try {
            return await Customer.find();
        } catch (error) {
            console.log(error);
            return error;
        }
    }
....

Setup / Version

Upvotes: 1

Views: 318

Answers (2)

Michał Lytek
Michał Lytek

Reputation: 12127

You should write a @FieldResolver which will fetch customers based on root user data. https://typegraphql.com/docs/resolvers.html#field-resolvers

Upvotes: 1

Eranga Heshan
Eranga Heshan

Reputation: 5814

In your resolver change the find operation like below:

return Customer.find({
  relations: ["user"]
});

Upvotes: 1

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