Setup
If you have completed the installation steps and setup the cargo prisma <command>
alias,
you are ready to add the Prisma Client Rust generator to your Prisma schema (opens in a new tab).
A common file layout is to give the schema and migrations their own folder:
Cargo.toml
src/
main.rs
prisma/
schema.prisma
migrations/
Below is an example of a schema located at prisma/schema.prisma
.
It uses a SQLite database and generates the client at src/prisma.rs
:
datasource db {
provider = "sqlite"
url = "file:dev.db"
}
generator client {
// Corresponds to the cargo alias created earlier
provider = "cargo prisma"
// The location to generate the client. Is relative to the position of the schema
output = "../src/prisma.rs"
}
model User {
id String @id
displayName String
}
Next, run cargo prisma generate
to generate the client that will be used in your Rust code.
If you have rustfmt
installed,
the generated code will be formatted for easier exploration and debugging.
The generated client must not be checked into source control.
It cannot be transferred between devices or operating systems.
You will need to re-generate it wherever you build your project.
If using git, add it to your .gitignore
file.
Creating the Client
First, make sure you are using the Tokio (opens in a new tab) async runtime. Other runtimes have not been tested, but since the Prisma Engines (opens in a new tab) use it there is likely no other option.
PrismaClient::_builder()
provides a builder API for customising the generated client.
The simplest use of this is calling .build()
directly on the builder.
Using the above schema for reference,
this builder creates a client in a main.rs
file right next to prisma.rs
:
// Stops the client from outputing a huge number of warnings during compilation.
#[allow(warnings, unused)]
mod prisma;
use prisma::PrismaClient;
use prisma_client_rust::NewClientError;
#[tokio::main]
async fn main() {
let client: Result<PrismaClient, NewClientError> = PrismaClient::_builder().build().await;
}
The with_url
builder method can be used to customise which database the client connects to.
In most cases it is recommended to control this with an environment variable in your schema,
but for some cases (eg. desktop apps with multiple databases) environment variables cannot be customised.
Naming Clashes
Rust has a reserved set of keywords (opens in a new tab) that cannot be used as names in your code.
If you name a model or field something that after conversion to snake_case
will be a restricted keyword,
it will be prefixed with r#
in the generated client instead of just failing to generate.