Enum Auto 

pub enum Auto<T> {
    Fixed(T),
    Auto,
}

Available on crate feature db only.

A wrapper over a value that can be either a fixed value or be automatically generated by the database.

This is primarily used for auto-incrementing primary keys.

Examples

use cot::db::{Auto, Model, model};

#[model]
struct MyModel {
    #[model(primary_key)]
    id: Auto<i32>,
}



let database = Database::new("sqlite::memory:").await?;

let mut my_model = MyModel { id: Auto::auto() };
my_model.save(&database).await?;
assert!(matches!(my_model.id, Auto::Fixed(_)));

Variants

Fixed(T)

A fixed value.

Auto

A value that will be automatically generated by the database.

Implementations

impl<T> Auto<T>

pub const fn auto() -> Self

Creates a new Auto instance that is automatically generated by the database.

Examples

use cot::db::Auto;

let auto = Auto::<i32>::auto();
assert!(matches!(auto, Auto::Auto));

pub const fn fixed(value: T) -> Self

Creates a new Auto instance with a fixed value.

Examples

use cot::db::Auto;

let auto = Auto::fixed(42);
assert!(matches!(auto, Auto::Fixed(42)));
assert_eq!(auto.unwrap(), 42);

pub fn unwrap(self) -> T

Returns the value, if the object is the Auto::Fixed variant; panics otherwise.

This is an equivalent of Option::unwrap.

Panics

If the object is the Auto::Auto variant.

Examples

use cot::db::Auto;

let auto = Auto::fixed(42);
assert_eq!(auto.unwrap(), 42);

pub fn expect(self, message: &str) -> T

Returns the value, if the object is the Auto::Fixed variant; panics with given message otherwise.

This is an equivalent of Option::expect.

Panics

If the object is the Auto::Auto variant.

Examples

use cot::db::Auto;

let auto = Auto::fixed(42);
assert_eq!(auto.expect("expected a fixed value"), 42);

Trait Implementations

impl<T: AsFormField> AsFormField for Auto<T>

type Type = <T as AsFormField>::Type

The form field type associated with the field.

fn new_field( options: FormFieldOptions, custom_options: <Self::Type as FormField>::CustomOptions, ) -> Self::Type

Creates a new form field with the given options and custom options.

fn clean_value(field: &Self::Type) -> Result<Self, FormFieldValidationError>

where Self: Sized,

Validates the value of the field and converts it to the final type. This method should return an error if the value is invalid.

fn to_field_value(&self) -> String

Returns self as a value that can be set with FormField::set_value.

impl<T: Clone> Clone for Auto<T>

fn clone(&self) -> Auto<T>

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<T: DatabaseField> DatabaseField for Auto<T>

const NULLABLE: bool = T::NULLABLE

Whether the field can be NULL in the database.

const TYPE: ColumnType = T::TYPE

The type of the column in the database as one of the variants of the ColumnType enum.

impl<T> Debug for Auto<T>

where T: Debug,

fn fmt(&self, __derive_more_f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<T> Default for Auto<T>

fn default() -> Self

Returns the “default value” for a type.

impl<T: Display> Display for Auto<T>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<T> From<T> for Auto<T>

fn from(value: T) -> Self

Converts to this type from the input type.

impl<T: DatabaseField> FromDbValue for Auto<T>

fn from_sqlite(value: SqliteValueRef<'_>) -> Result<Self>

where Self: Sized,

Available on crate feature sqlite only.

Converts the given SQLite database value to a Rust value.

fn from_postgres(value: PostgresValueRef<'_>) -> Result<Self>

where Self: Sized,

Available on crate feature postgres only.

Converts the given PostgreSQL database value to a Rust value.

fn from_mysql(value: MySqlValueRef<'_>) -> Result<Self>

where Self: Sized,

Available on crate feature mysql only.

Converts the given MySQL database value to a Rust value.

impl<T: FromStr> FromStr for Auto<T>

type Err = <T as FromStr>::Err

The associated error which can be returned from parsing.

fn from_str(s: &str) -> Result<Self, Self::Err>

Parses a string s to return a value of this type.

impl<T: Hash> Hash for Auto<T>

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl<T: PartialEq> PartialEq for Auto<T>

fn eq(&self, other: &Auto<T>) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<T: DatabaseField> ToDbFieldValue for Auto<T>

fn to_db_field_value(&self) -> DbFieldValue

Converts the Rust value to a DbFieldValue that indicates whether the value should be automatically generated by the database, or contains a specific, explicitly provided value.

impl<T: Copy> Copy for Auto<T>

impl<T: Eq> Eq for Auto<T>

impl<T: PrimaryKey> PrimaryKey for Auto<T>

impl<T> StructuralPartialEq for Auto<T>