Trait DatabaseField

pub trait DatabaseField: FromDbValue + ToDbFieldValue {
    const TYPE: ColumnType;
    const NULLABLE: bool = false;
}

Available on crate feature db only.

A trait denoting that some type can be used as a field in a database.

Required Associated Constants

const TYPE: ColumnType

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

Changing the column type after initial implementation

Note that this should never be changed after the type is implemented. The migration generator is unable to detect a change in the column type and will not generate a migration for it. If the column type needs to be changed, a manual migration should be written, or a new type should be created.

This is especially important for types that are stored as fixed-length strings in the database, as the migration generator cannot detect a change in the string length. For this reason, it’s recommended to use the LimitedString type for fixed-length strings (which uses const generics, so each change in the length will be a new type) instead of a custom type with a fixed length.

Provided Associated Constants

const NULLABLE: bool = false

Whether the field can be NULL in the database.

This is false by default, meaning that the field is required in the database. This is set to true for Option types.

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementations on Foreign Types

impl DatabaseField for bool

const TYPE: ColumnType = ColumnType::Boolean

impl DatabaseField for f32

const TYPE: ColumnType = ColumnType::Float

impl DatabaseField for f64

const TYPE: ColumnType = ColumnType::Double

impl DatabaseField for i8

const TYPE: ColumnType = ColumnType::TinyInteger

impl DatabaseField for i16

const TYPE: ColumnType = ColumnType::SmallInteger

impl DatabaseField for i32

const TYPE: ColumnType = ColumnType::Integer

impl DatabaseField for i64

const TYPE: ColumnType = ColumnType::BigInteger

impl DatabaseField for u8

const TYPE: ColumnType = ColumnType::TinyUnsignedInteger

impl DatabaseField for u16

const TYPE: ColumnType = ColumnType::SmallUnsignedInteger

impl DatabaseField for u32

const TYPE: ColumnType = ColumnType::UnsignedInteger

impl DatabaseField for u64

const TYPE: ColumnType = ColumnType::BigUnsignedInteger

impl DatabaseField for String

const TYPE: ColumnType = ColumnType::Text

impl DatabaseField for Vec<u8>

const TYPE: ColumnType = ColumnType::Blob

impl DatabaseField for DateTime<FixedOffset>

const TYPE: ColumnType = ColumnType::DateTimeWithTimeZone

impl DatabaseField for NaiveDate

const TYPE: ColumnType = ColumnType::Date

impl DatabaseField for NaiveDateTime

const TYPE: ColumnType = ColumnType::DateTime

impl DatabaseField for NaiveTime

const TYPE: ColumnType = ColumnType::Time

impl<T: DatabaseField> DatabaseField for Option<T>

where Option<T>: ToDbFieldValue + FromDbValue,

const NULLABLE: bool = true

const TYPE: ColumnType = T::TYPE

Implementors

impl DatabaseField for PasswordHash

const TYPE: ColumnType

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

const NULLABLE: bool = T::NULLABLE

const TYPE: ColumnType = T::TYPE

impl<T: Model + Send + Sync> DatabaseField for ForeignKey<T>

const NULLABLE: bool = <T::PrimaryKey>::NULLABLE

const TYPE: ColumnType = <T::PrimaryKey>::TYPE

impl<const LIMIT: u32> DatabaseField for LimitedString<LIMIT>

const TYPE: ColumnType