Using multiple fields for a unique key in Prisma
I ran into an issue with Prisma that made me lose a bit of time, so I’ll write how I solved it.
The model didn’t have an id
field marked as @id
so I added a @@unique()
to say user
and tweet
, together, defined the unique
constrain.
model Like {
user Int
tweet Int
createdAt DateTime @default(now())
@@unique([user, tweet])
}
This means we can’t have more than 1 same entries of (user, tweet)
entries.
When I tried to delete an entry with
await prisma.like.delete({
where: {
user: 1,
tweet: 1
}
})
I run into an error message:
PrismaClientValidationError:
Invalid `prisma.like.delete()` invocation:
{
where: {
user: 12,
~~~~
tweet: 22
~~~~~
}
~~~~~~~~~~~
}
Argument where of type LikeWhereUniqueInput needs exactly one argument, but you provided user and tweet. Please choose one. Available args:
type LikeWhereUniqueInput {
user_tweet?: LikeUserTweetCompoundUniqueInput
}
What I had to do was change
await prisma.like.delete({
where: {
user: 1,
tweet: 1
}
})
to
await prisma.like.delete({
where: {
user_tweet: {
user: 1,
tweet: 1
}
}
})
In other words, combining the unique fields concatenating them with an underscore.
In retrospect the error message was sort of explaining this, but I didn’t get it.
→ I wrote 17 books to help you become a better developer, download them all at $0 cost by joining my newsletter
→ JOIN MY CODING BOOTCAMP, an amazing cohort course that will be a huge step up in your coding career - covering React, Next.js - next edition February 2025