Trait mysql_async::prelude::FromValue

pub trait FromValue {
    type Intermediate: ConvIr<Self>;
    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 value to something.

FromRow requires ability to cheaply rollback FromValue conversion. This ability is provided via Intermediate associated type.

Example implementation:

#[derive(Debug)]
pub struct StringIr {
    bytes: Vec<u8>,
}

impl ConvIr<String> for StringIr {
    fn new(v: Value) -> MyResult<StringIr> {
        match v {
            Value::Bytes(bytes) => match from_utf8(&*bytes) {
                Ok(_) => Ok(StringIr { bytes: bytes }),
                Err(_) => Err(Error::FromValueError(Value::Bytes(bytes))),
            },
            v => Err(Error::FromValueError(v)),
        }
    }
    fn commit(self) -> String {
        unsafe { String::from_utf8_unchecked(self.bytes) }
    }
    fn rollback(self) -> Value {
        Value::Bytes(self.bytes)
    }
}

impl FromValue for String {
    type Intermediate = StringIr;
}

Associated Types

type Intermediate: ConvIr<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.

Implementations on Foreign Types

impl FromValue for i32

type Intermediate = ParseIr<i32>

fn from_value(v: Value) -> i32

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

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

impl FromValue for String

type Intermediate = StringIr

fn from_value(v: Value) -> String

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

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

impl FromValue for i16

type Intermediate = ParseIr<i16>

fn from_value(v: Value) -> i16

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

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

impl FromValue for f32

type Intermediate = ParseIr<f32>

fn from_value(v: Value) -> f32

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

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

impl FromValue for i64

type Intermediate = ParseIr<i64>

fn from_value(v: Value) -> i64

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

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

impl FromValue for f64

type Intermediate = ParseIr<f64>

fn from_value(v: Value) -> f64

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

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

impl FromValue for isize

type Intermediate = ParseIr<isize>

fn from_value(v: Value) -> isize

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

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

impl FromValue for u8

type Intermediate = ParseIr<u8>

fn from_value(v: Value) -> u8

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

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

impl FromValue for Vec<u8>

type Intermediate = BytesIr

fn from_value(v: Value) -> Vec<u8>

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

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

impl FromValue for i8

type Intermediate = ParseIr<i8>

fn from_value(v: Value) -> i8

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

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

impl<T> FromValue for Option<T> where
    T: FromValue, 

type Intermediate = OptionIr<<T as FromValue>::Intermediate>

fn from_value(v: Value) -> Option<T>

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

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

impl FromValue for Value

type Intermediate = JsonIr

fn from_value(v: Value) -> Self

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

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

impl FromValue for u32

type Intermediate = ParseIr<u32>

fn from_value(v: Value) -> u32

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

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

impl FromValue for u64

type Intermediate = ParseIr<u64>

fn from_value(v: Value) -> u64

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

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

impl FromValue for Duration

type Intermediate = ParseIr<Duration>

fn from_value(v: Value) -> Duration

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

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

impl FromValue for bool

type Intermediate = ParseIr<bool>

fn from_value(v: Value) -> bool

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

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

impl FromValue for u16

type Intermediate = ParseIr<u16>

fn from_value(v: Value) -> u16

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

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

impl FromValue for usize

type Intermediate = ParseIr<usize>

fn from_value(v: Value) -> usize

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

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

Implementors

• impl<T> FromValue for Deserialized<T> where
    T: DeserializeOwned,  type Intermediate = DeserializedIr<T>;
• impl FromValue for NaiveTime type Intermediate = ParseIr<NaiveTime>;
• impl FromValue for mysql_async::time::Duration type Intermediate = ParseIr<Duration>;
• impl FromValue for NaiveDate type Intermediate = ParseIr<NaiveDate>;
• impl FromValue for Uuid type Intermediate = UuidIr;
• impl FromValue for Timespec type Intermediate = ParseIr<Timespec>;
• impl FromValue for mysql_async::Value type Intermediate = Value;
• impl FromValue for NaiveDateTime type Intermediate = ParseIr<NaiveDateTime>;