Trait EnumMapping 

pub trait EnumMapping<DB: Backend> {
    // Required methods
    fn map_to_database_value<'b>(
        output: &mut Output<'b, '_, DB>,
        variant: &'static EnumVariant,
    ) -> Result;
    fn map_from_database_value(
        raw: DB::RawValue<'_>,
        type_name: &'static str,
        variants: &'static [EnumVariant],
    ) -> Result<usize>;
}

Available on crate feature i-implement-a-third-party-backend-and-opt-into-breaking-changes only.

A helper trait to describe mapping an enum between rust values and database values

This is implemented for different mapping strategies, some of them might be database dependent, while others might be independent

Required Methods

fn map_to_database_value<'b>( output: &mut Output<'b, '_, DB>, variant: &'static EnumVariant, ) -> Result

Map an enum variant to the database representation

fn map_from_database_value( raw: DB::RawValue<'_>, type_name: &'static str, variants: &'static [EnumVariant], ) -> Result<usize>

Construct an enum variant from the database representation

This is expected to return the index of the variant in the variants array

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors

impl EnumMapping<Mysql> for EnumTypeMapping

Available on crate feature mysql_backend only.

impl EnumMapping<Pg> for EnumTypeMapping

Available on crate feature postgres_backend only.

impl<DB> EnumMapping<DB> for StringMapping

where DB: Backend, for<'a> &'a str: FromSqlRef<'a, Text, DB>, &'static str: ToSql<Text, DB>,

impl<T, ST, DB> EnumMapping<DB> for IntMapping<T, ST>

where for<'a> DB: Backend<BindCollector<'a> = RawBytesBindCollector<DB>>, T: ToSql<ST, DB> + FromSql<ST, DB>, i128: TryInto<T, Error: Display> + TryFrom<T, Error: Display>,

impl<T, ST> EnumMapping<Sqlite> for IntMapping<T, ST>

where T: ToSql<ST, Sqlite> + FromSql<ST, Sqlite>, for<'a> SqliteBindValue<'a>: From<T>, i128: TryInto<T, Error: Display> + TryFrom<T, Error: Display>,

Available on crate feature __sqlite-shared only.