I need to create a relationship with NestJs, GraphQL and prisma - nestjs

Question

I need to create one to many relationship between transaction and the user.
so the user can have multiple transactions, but the transaction can only have one user. I made the relationship in prisma, but the thing is how do I achieve this in nestjs with prisma that is the problem I'm getting. I added to the code section so I'll appreciate any help thanks.
schema.prisma :
generator client {
provider = "prisma-client-js"
}
datasource db {
provider = "postgresql"
url = env("DATABASE_URL")
}
model Crowdfund {
id String #id #default(uuid())
title String
description String
location String
target Int
image String?
}
model Institution {
institutionId String #id #default(uuid())
institutionName String
phone String
email String
location String
}
model User {
id String #id #default(uuid())
userName String
userPhone String?
password String
email String #unique
location String?
transactions Transaction[]
}
model Transaction {
id String #id #default(uuid())
amount Int
createdAt DateTime #default(now())
userId String
user User #relation(fields: [userId], references: [id])
}
create-dto from transaction :
import { InputType, Int, Field } from '#nestjs/graphql';
#InputType()
export class CreateTransactionInput {
#Field(() => Int)
amount: number;
#Field({nullable: true})
createdAt?: Date;
#Field()
userId: string;
}
entites from transaction :
import { ObjectType, Field, Int} from '#nestjs/graphql';
import { User } from 'src/user/entities/user.entity';
#ObjectType()
export class Transaction {
#Field()
id: string;
#Field(() => Int)
amount: number;
#Field()
createdAt: Date;
#Field(() => User)
user: User;
#Field()
userId: string;
}
transaction.service.ts :
import { Injectable } from '#nestjs/common';
import { PrismaService } from 'prisma/prisma.service';
import { CreateTransactionInput } from './dto/create-transaction.input';
import { UpdateTransactionInput } from './dto/update-transaction.input';
#Injectable()
export class TransactionService {
constructor(
private prismService: PrismaService
) {}
create(createTransactionInput: CreateTransactionInput) {
return this.prismService.transaction.create({data: createTransactionInput})
}
findAll() {
return this.prismService.transaction.findMany();
}
findOne(id: string) {
return this.prismService.transaction.findUnique({where: {id: id}})
}
update(id: string, updateTransactionInput: UpdateTransactionInput) {
return this.prismService.transaction.update({data: updateTransactionInput, where: {id: id}})
}
remove(id: string) {
return this.prismService.transaction.delete({where: {id: id}})
}
}
create-dto from user:
import { InputType, Int, Field } from '#nestjs/graphql';
import { IsEmail, IsNotEmpty, IsString, MinLength } from 'class-validator';
#InputType()
export class CreateUserInput {
#IsString()
#IsNotEmpty()
#MinLength(3)
#Field()
userName: string;
#IsString()
#IsNotEmpty()
#Field({nullable: true})
userPhone?: string;
#IsString()
#IsNotEmpty()
#MinLength(3)
#Field()
password: string
#IsString()
#IsNotEmpty()
#MinLength(3)
#IsEmail()
#Field()
email: string;
#IsString()
#IsNotEmpty()
#Field({nullable: true})
location?: string;
}
entities from user
import { ObjectType, Field, Int } from '#nestjs/graphql';
import { Transaction } from '../../transaction/entities/transaction.entity';
#ObjectType()
export class User {
#Field()
id: string;
#Field()
userName: string;
#Field({nullable: true})
userPhone?: string;
#Field()
email: string;
#Field({nullable: true})
location?: string;
#Field(() => [Transaction], {nullable: true})
transaction: Transaction
}
user.service.ts :
import { Injectable } from '#nestjs/common';
import { PrismaService } from 'prisma/prisma.service';
import { CreateUserInput } from './dto/create-user.input';
import { UpdateUserInput } from './dto/update-user.input';
#Injectable()
export class UserService {
constructor(
private prismService: PrismaService
){}
create(createUserInput: CreateUserInput) {
return this.prismService.user.create({data: createUserInput});
}
findAll() {
return this.prismService.user.findMany({include: {transactions: true}});
}
findOne(id: string) {
return this.prismService.user.findUnique({where: {id: id}})
}
update(id: string, updateUserInput: UpdateUserInput) {
return this.prismService.user.update({data: updateUserInput, where: {id: id}})
}
remove(id: string) {
return this.prismService.user.delete({where: {id: id}})
}
}