model Post{
//...
place Place[] #relation(fields: [placeId], references: [id])
placeId Int
}
model Place{
//...
post Post #relation(fields: [postId], references: [id])
postId Int
}
when I do this,
I got this error
error: Error parsing attribute "#relation": The relation field place on Model Post must not specify the fields or references argument in the #relation attribute. You must only specif
y it on the opposite field post on model Place.
how to fix this??
and I don`t understand difference between
just simple post Post (without #relation)
and
post Post #relation(...)
A relation is used to show a connection between two entities or models in the Prisma schema. To fix your issue, you would do something like
model Post{
id Int #id #default(autoincrement())
place Place[]
}
model Place{
id Int #id #default(autoincrement())
post Post #relation(fields: [postId], references: [id])
postId Int
}
To learn more about relations, please do take a look at the docs
For an implicit many-to-many relation, you can do
model Post{
id Int #id #default(autoincrement())
place Place[]
}
model Place{
id Int #id #default(autoincrement())
post Post[]
postId Int
}
Related
Looking at the Prisma docs and they show the example below. In this instance, if I'm using MongoDB and define my schema as per below, does Prisma create a collection for me called _CategoryToPost on my behalf to record the many to many relationships?
Or do I have to create my own collection to document this relationship?
model User {
id Int #id #default(autoincrement())
email String #unique
name String?
role Role #default(USER)
posts Post[]
profile Profile?
}
model Profile {
id Int #id #default(autoincrement())
bio String
user User #relation(fields: [userId], references: [id])
userId Int #unique
}
model Post {
id Int #id #default(autoincrement())
createdAt DateTime #default(now())
title String
published Boolean #default(false)
author User #relation(fields: [authorId], references: [id])
authorId Int
categories Category[] #relation(references: [id])
}
model Category {
id Int #id #default(autoincrement())
name String
posts Post[] #relation(references: [id])
}
enum Role {
USER
ADMIN
}
Link to docs
Prisma will create the necessary collections when you run the npx prisma db push command. You should not need to worry about the underlying structure beyond that.
I'm having trouble conceptualizing how to handle this issue. I've pored through the Prisma docs and other SO questions, but they all seem to be slightly different from this situation.
I have two models:
model User {
id Int #id #default(autoincrement())
firstName String? #map("first_name")
lastName String? #map("last_name")
email String #unique
password String
role UserRole #default(value: USER)
image String? #map("image")
createdAt DateTime #default(now()) #map("created_at")
updatedAt DateTime #updatedAt #map("updated_at")
friends Friend[]
##map("users")
}
model Friend {
id Int #id #default(autoincrement())
inviteSentOn DateTime #map("invite_sent_on") #db.Timestamptz(1)
inviteAcceptedOn DateTime #map("invite_accepted_on") #db.Timestamptz(1)
userId Int #map("user_id")
friendId Int #map("friend_id")
createdAt DateTime #default(now()) #map("created_at")
updatedAt DateTime #updatedAt #map("updated_at")
user User #relation(fields: [userId], references: [id])
// friend User? #relation(name: "FriendFriend", fields: [friendId], references: [id])
##map("friends")
}
I want to be able to set up the relationships on the Friend model to both point towards the User model, however I receive errors such as Error validating field 'friend' in model 'Friend': The relation field 'friend' on Model 'Friend' is missing an opposite relation field on the model 'User'.
I've tried adding the name property to the #relation field, but start receiving errors about ambiguous relations being detected.
How do I go about setting these relations up correctly?
You just need to provide name to disambiguate relation, like that:
model User {
id Int #id #default(autoincrement())
friend Friend?
friends Friend[] #relation(name: "friends")
}
model Friend {
id Int #id #default(autoincrement())
userId Int
friendId Int
user User #relation(fields: [userId], references: [id])
friend User #relation(fields: [friendId], references: [id], name: "friends")
}
And dont forget that both sides of relations need to have connections to the other.
I want to acomplish such schema, where user could have some images and recipes could have some images.
I came up with solution, but it throws this error for author and recipe rows in image model. My solution is to use type column as diferentiator between Recipe and User types.
Error parsing attribute "#relation": The given constraint name images_parentId_fkey has to be unique in the following namespace: on model Image for primary key, indexes, unique constraints and foreign keys. Please provide a different name using the map argument.
My solution:
model User {
id String #id #unique #default(dbgenerated("gen_random_uuid()")) #db.Uuid
images Image[] #relation("UserImages")
Recipe Recipe[] #relation("RecipeAuthor")
##map("users")
}
model Recipe {
id String #id #unique #default(dbgenerated("gen_random_uuid()")) #db.Uuid
authorId String #db.Uuid
author User #relation("RecipeAuthor", fields: [authorId], references: [id])
images Image[] #relation("RecipeImages")
##map("recipes")
}
model Image {
id String #id #unique #default(dbgenerated("gen_random_uuid()")) #db.Uuid
type String
parentId String #db.Uuid
author User #relation("UserImages", fields: [parentId], references: [id])
recipe Recipe #relation("RecipeImages", fields: [parentId], references: [id])
##map("images")
}
Only other solution I came up with is to create multiple tables for images, something like user_images and recipe_images, but i dont really like that and I might need even more tables like this in future, so I would rather find better way. Thanks in advance for any help :)
Instead of using parentId for both in UserImages and ReceipeImages relation. You can separate them out and have something like parentUserId and parentReceipeId.
The following solution could potentially work:
model User {
id String #id #unique #default(dbgenerated("gen_random_uuid()")) #db.Uuid
images Image[] #relation("UserImages")
Recipe Recipe[] #relation("RecipeAuthor")
##map("users")
}
model Recipe {
id String #id #unique #default(dbgenerated("gen_random_uuid()")) #db.Uuid
authorId String #db.Uuid
author User #relation("RecipeAuthor", fields: [authorId], references: [id])
images Image[] #relation("RecipeImages")
##map("recipes")
}
model Image {
id String #id #unique #default(dbgenerated("gen_random_uuid()")) #db.Uuid
type String
parentUserId String? #db.Uuid
parentReceipeId String? #db.Uuid
author User? #relation("UserImages", fields: [parentUserId], references: [id])
recipe Recipe? #relation("RecipeImages", fields: [parentReceipeId], references: [id])
##map("images")
}
I'm learning Prisma,
I want to leverage Prisma's Implicit relations as much as possible for the following relation (and later I want to use nexus for writing queries):
1 User can belong to Many Conversations (as it's participant)
1 Conversation has an array os users (called participants)
1 User can own Many Messages (as it's author)
1 Message can have 1 User (as it's author)
1 Conversation has an array of messages (called texts)
1 Message can only belong to 1 Conversation
So far I have come up with this (but I highly doubt it's correct because its not behaving as I want it to when using with nexus):
model User {
id String #id #default(uuid())
conversations Conversation[]
}
model Message {
id String #id #default(uuid())
authorId String
conversationId String
author User #relation(fields: [authorId], references: [id])
conversation Conversation #relation(fields: [conversationId], references: [id])
}
model Conversation {
id String #id #default(uuid())
participants User[]
messages Message[]
}
Could I please get some pointers/help to proceed?
following your requirements list this schema is pretty much ready. Just add the messages field on the User model to declare its side of the relationship.
It would be like this:
model User {
id String #id #default(uuid())
conversations Conversation[]
messages Message[]
}
model Message {
id String #id #default(uuid())
authorId String
conversationId String
author User #relation(fields: [authorId], references: [id])
conversation Conversation #relation(fields: [conversationId], references: [id])
}
model Conversation {
id String #id #default(uuid())
participants User[]
messages Message[]
}
Do you have any specific issues that occur when using Nexus with it?
I have a video tutorial that might help you with some extra guidance:
https://www.youtube.com/watch?v=sWlzqRB5Xro
I believe this schema would solve it to you. If you want to know more, I gave a talk about this topic a while back.
model User {
id String #id #default(uuid())
messages Message[]
conversations Conversation[]
}
model Message {
id String #id #default(uuid())
author User #relation(fields: [authorId], references: [id])
authorId String
conversation Conversation #relation(fields: [conversationId], references: [id])
conversationId String
}
model Conversation {
id String #id #default(uuid())
messages Message[]
members User[]
}
I wonder why my model (the Like-model) does not work as I expect it to.
Maybe someone can explain?
model User {
id Int #id #default(autoincrement())
likes Like[]
}
model Like {
fromUser User #relation(fields: [fromUserId] references: [id])
fromUserId Int
toUser User #relation(fields: [toUserId] references: [id])
toUserId Int
##id([fromUserId, toUserId])
}
The error reads: Error validating: This line is not a valid field or attribute definition.
It points at fromUser User #relation(fields: [fromUserId] references: [id]) and toUser User #relation(fields: [toUserId] references: [id]).
You would need to model your relations in the following manner:
model User {
id Int #id #default(autoincrement())
likedUsers Like[] #relation("likedUsers")
usersWhoLiked Like[] #relation("usersWhoLiked")
}
model Like {
id Int #id #default(autoincrement())
likedUser User? #relation("likedUsers", fields: [likedUserId], references: [id])
likedUserId Int?
userWhoLiked User? #relation("usersWhoLiked", fields: [userWhoLikedId], references: [id])
userWhoLikedId Int?
}
Whenever you have more than 1 relation to a model you need to provide a relation name to disambiguate the relation.
Also you need to store which users you have liked and who liked the current user. So you would need two relations for this.
Missing commas.
The solution might look like this:
model User {
id Int #id #default(autoincrement())
likes Like[]
}
model Like {
fromUser User #relation(fields: [fromUserId], references: [id])
fromUserId Int
toUser User #relation(fields: [toUserId], references: [id])
toUserId Int
##id([fromUserId, toUserId])
}