Updating Records

Toasty generates an update builder for each model. You can update a record through an instance method, through a query, or with a generated convenience method.

Updating an instance

Call .update() on a mutable model instance, set the fields you want to change, and call .exec(&mut db):

#![allow(unused)]
fn main() {
use toasty::Model;
#[derive(Debug, toasty::Model)]
struct User {
    #[key]
    #[auto]
    id: u64,
    name: String,
    #[unique]
    email: String,
}
async fn __example(mut db: toasty::Db) -> toasty::Result<()> {
let mut user = User::create()
    .name("Alice")
    .email("alice@example.com")
    .exec(&mut db)
    .await?;

user.update()
    .name("Alice Smith")
    .exec(&mut db)
    .await?;

// The instance is updated in place
assert_eq!(user.name, "Alice Smith");
Ok(())
}
}

Only set the fields you want to change. Fields you don’t set keep their current values. The .update() method takes &mut self, so you need a mutable binding. After .exec() completes, the instance reflects the new values.

The generated SQL looks like:

UPDATE users SET name = 'Alice Smith' WHERE id = 1;

Updating multiple fields

Chain multiple setters to update several fields at once:

#![allow(unused)]
fn main() {
use toasty::Model;
#[derive(Debug, toasty::Model)]
struct User {
    #[key]
    #[auto]
    id: u64,
    name: String,
    #[unique]
    email: String,
}
async fn __example(mut db: toasty::Db) -> toasty::Result<()> {
let mut user = User::create()
    .name("Alice")
    .email("alice@example.com")
    .exec(&mut db)
    .await?;
user.update()
    .name("Alice Smith")
    .email("alice.smith@example.com")
    .exec(&mut db)
    .await?;
Ok(())
}
}

Updating by query

You can update records without first loading them by building a query and calling .update() on it:

#![allow(unused)]
fn main() {
use toasty::Model;
#[derive(Debug, toasty::Model)]
struct User {
    #[key]
    #[auto]
    id: u64,
    name: String,
    #[unique]
    email: String,
}
async fn __example(mut db: toasty::Db, user_id: u64) -> toasty::Result<()> {
User::filter_by_id(user_id)
    .update()
    .name("Bob")
    .exec(&mut db)
    .await?;
Ok(())
}
}

This executes the update directly without loading the record first. The query determines which records to update, and the chained setters specify the new values.

Update by indexed field

Toasty generates update_by_* convenience methods for key and indexed fields:

#![allow(unused)]
fn main() {
use toasty::Model;
#[derive(Debug, toasty::Model)]
struct User {
    #[key]
    #[auto]
    id: u64,
    name: String,
    #[unique]
    email: String,
}
async fn __example(mut db: toasty::Db, user_id: u64) -> toasty::Result<()> {
User::update_by_id(user_id)
    .name("Bob")
    .exec(&mut db)
    .await?;
Ok(())
}
}

This is shorthand for User::filter_by_id(user_id).update(). Toasty generates update_by_* for each field that has #[key], #[unique], or #[index].

Setting optional fields to None

To clear an optional field, pass None with the appropriate type annotation:

#![allow(unused)]
fn main() {
use toasty::Model;
#[derive(Debug, toasty::Model)]
struct User {
    #[key]
    #[auto]
    id: u64,
    name: String,
    bio: Option<String>,
}
async fn __example(mut db: toasty::Db) -> toasty::Result<()> {
let mut user = User::create()
    .name("Alice")
    .bio("Likes Rust")
    .exec(&mut db)
    .await?;
user.update()
    .bio(Option::<String>::None)
    .exec(&mut db)
    .await?;

assert!(user.bio.is_none());
Ok(())
}
}

What gets generated

For a model with #[key] on id and #[unique] on email, Toasty generates:

• user.update() — instance method (takes &mut self), returns an update builder. After .exec(), the instance is reloaded with the new values.
• User::update_by_id(id) — returns an update builder for the record matching the given key.
• User::update_by_email(email) — returns an update builder for the record matching the given email.
• Any query builder’s .update() method — converts the query into an update builder.

The update builder has a setter method for each field. Only the fields you set are included in the UPDATE statement.