Trait FromValue

pub trait FromValue: Sized {
    type Intermediate: TryFrom<Value, Error = FromValueError> + Into<Self>;

    // Provided methods
    fn from_value(v: Value) -> Self { ... }
    fn from_value_opt(v: Value) -> Result<Self, FromValueError> { ... }
    fn get_intermediate(v: Value) -> Result<Self::Intermediate, FromValueError> { ... }
}

Implement this trait to convert a value to some type.

The FromRow trait requires an ability to rollback this conversion to an original Value instance. Thats the reason why there is the Intermediate type – consider implementing Into<Value> for your Intermediate type if you want FromRow to work with your type.

Required Associated Types

type Intermediate: TryFrom<Value, Error = FromValueError> + Into<Self>

Provided Methods

fn from_value(v: Value) -> Self

Will panic if could not convert v to Self.

fn from_value_opt(v: Value) -> Result<Self, FromValueError>

Will return Err(Error::FromValueError(v)) if could not convert v to Self.

fn get_intermediate(v: Value) -> Result<Self::Intermediate, FromValueError>

Will return Err(Error::FromValueError(v)) if v is not convertible to Self.

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 FromValue for Cow<'static, str>

type Intermediate = String

impl FromValue for Cow<'static, [u8]>

type Intermediate = Cow<'static, [u8]>

impl FromValue for Value

type Intermediate = ParseIr<Value>

impl FromValue for bool

type Intermediate = ParseIrOpt<bool>

impl FromValue for f32

type Intermediate = ParseIrOpt<f32>

impl FromValue for f64

type Intermediate = ParseIrOpt<f64>

impl FromValue for i8

type Intermediate = ParseIrOpt<i8>

impl FromValue for i16

type Intermediate = ParseIrOpt<i16>

impl FromValue for i32

type Intermediate = ParseIrOpt<i32>

impl FromValue for i64

type Intermediate = ParseIrOpt<i64>

impl FromValue for i128

type Intermediate = ParseIrOpt<i128>

impl FromValue for isize

type Intermediate = ParseIrOpt<isize>

impl FromValue for u8

type Intermediate = ParseIrOpt<u8>

impl FromValue for u16

type Intermediate = ParseIrOpt<u16>

impl FromValue for u32

type Intermediate = ParseIrOpt<u32>

impl FromValue for u64

type Intermediate = ParseIrOpt<u64>

impl FromValue for u128

type Intermediate = ParseIrOpt<u128>

impl FromValue for usize

type Intermediate = ParseIrOpt<usize>

impl FromValue for String

type Intermediate = String

impl FromValue for Vec<u8>

type Intermediate = Vec<u8>

impl FromValue for Duration

type Intermediate = ParseIrOpt<Duration>

impl FromValue for BigDecimal

type Intermediate = ParseIr<BigDecimal>

impl FromValue for NaiveDate

type Intermediate = ParseIr<NaiveDate>

impl FromValue for NaiveDateTime

type Intermediate = ParseIr<NaiveDateTime>

impl FromValue for NaiveTime

type Intermediate = ParseIr<NaiveTime>

impl FromValue for BigInt

type Intermediate = ParseIr<BigInt>

impl FromValue for BigUint

type Intermediate = ParseIr<BigUint>

impl FromValue for Decimal

type Intermediate = ParseIr<Decimal>

impl FromValue for Date

type Intermediate = ParseIr<Date>

impl FromValue for Duration

type Intermediate = ParseIr<Duration>

impl FromValue for PrimitiveDateTime

type Intermediate = ParseIr<PrimitiveDateTime>

impl FromValue for Time

Converts a MySQL TIME value to a time::Time. Note: time::Time only allows for time values in the 00:00:00 - 23:59:59 range. If you’re expecting TIME values in MySQL’s TIME value range of -838:59:59 - 838:59:59, use time::Duration instead.

type Intermediate = ParseIr<Time>

impl FromValue for Uuid

type Intermediate = ParseIr<Uuid>

impl<T> FromValue for Option<T>

where T: FromValue,

type Intermediate = OptionIr2<T>

impl<const N: usize> FromValue for [u8; N]

type Intermediate = [u8; N]

Implementors

impl FromValue for mysql_async::Value

type Intermediate = ValueIr

impl<T> FromValue for Deserialized<T>

where T: DeserializeOwned,

type Intermediate = ParseIr<Deserialized<T>>