P
Prisma•3d ago
Hydroper

Dependency-dependents relations

I am having difficulty understanding whether my schema is correct, even if it reports no errors. It's basically that I'm trying to express a package registry as part of a package manager, and am having difficulty specifying dependencies and dependents relations as part of the PackageVersion model. 
model PackageVersion {
  id                  BigInt                   @id @default(autoincrement())
  versionNumber       String
  publishedAt         DateTime                 @default(now())
  zip                 Bytes
  package             Package                  @relation(fields: [packageId], references: [id])
  packageId           BigInt
  dependencies        PackageVersion[]         @relation("Dependency")
  dependents          PackageVersion[]         @relation("Dependency")
  yanked              Boolean                  @default(false)
}
model PackageVersion {
  id                  BigInt                   @id @default(autoincrement())
  versionNumber       String
  publishedAt         DateTime                 @default(now())
  zip                 Bytes
  package             Package                  @relation(fields: [packageId], references: [id])
  packageId           BigInt
  dependencies        PackageVersion[]         @relation("Dependency")
  dependents          PackageVersion[]         @relation("Dependency")
  yanked              Boolean                  @default(false)
}
2 Replies
Hydroper
HydroperOP•2d ago
I give up on Prisma -_-
RaphaelEtim
RaphaelEtim•this hour
Hi 👋 I think the confusion stems from having the same relation name Dependency for both dependencies and dependents fields. Also, from your code, you are trying to create a self-referencing many-to-many relationship for package dependencies. To properly express this relationship, you need to use distinct names for each side of the relation and add the necessary fields to make it an explicit many-to-many relationship. For example: 
model PackageVersion {
  id                  BigInt                   @id @default(autoincrement())
  versionNumber       String
  publishedAt         DateTime                 @default(now())
  zip                 Bytes
  package             Package                  @relation(fields: [packageId], references: [id])
  packageId           BigInt
  dependencies        PackageDependency[]      @relation("DependencyTo")
  dependents          PackageDependency[]      @relation("DependencyFrom")
  yanked              Boolean                  @default(false)
}

model PackageDependency {
  id                  BigInt                   @id @default(autoincrement())
  dependencyVersion   PackageVersion           @relation("DependencyTo", fields: [dependencyVersionId], references: [id])
  dependencyVersionId BigInt
  dependentVersion    PackageVersion           @relation("DependencyFrom", fields: [dependentVersionId], references: [id])
  dependentVersionId  BigInt

  @@unique([dependencyVersionId, dependentVersionId])
}
model PackageVersion {
  id                  BigInt                   @id @default(autoincrement())
  versionNumber       String
  publishedAt         DateTime                 @default(now())
  zip                 Bytes
  package             Package                  @relation(fields: [packageId], references: [id])
  packageId           BigInt
  dependencies        PackageDependency[]      @relation("DependencyTo")
  dependents          PackageDependency[]      @relation("DependencyFrom")
  yanked              Boolean                  @default(false)
}

model PackageDependency {
  id                  BigInt                   @id @default(autoincrement())
  dependencyVersion   PackageVersion           @relation("DependencyTo", fields: [dependencyVersionId], references: [id])
  dependencyVersionId BigInt
  dependentVersion    PackageVersion           @relation("DependencyFrom", fields: [dependentVersionId], references: [id])
  dependentVersionId  BigInt

  @@unique([dependencyVersionId, dependentVersionId])
}
Looking at the example i shared, I've introduced a new PackageDependency model to represent the many-to-many relationship explicitly. The dependencies field in PackageVersion now uses the relation name DependencyTo, representing the versions that this package depends on. The dependents field in PackageVersion uses the relation name DependencyFrom, representing the versions that depend on this package. The PackageDependency model has two fields referencing PackageVersion, one for the dependency and one for the dependent. You may also want to share your full schema in order for us to help you further.

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