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use super::{ValueRef, Value};
use std::error::Error;
use std::fmt;
#[derive(Debug)]
pub enum FromSqlError {
InvalidType,
Other(Box<Error + Send + Sync>),
}
impl fmt::Display for FromSqlError {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
match *self {
FromSqlError::InvalidType => write!(f, "Invalid type"),
FromSqlError::Other(ref err) => err.fmt(f),
}
}
}
impl Error for FromSqlError {
fn description(&self) -> &str {
match *self {
FromSqlError::InvalidType => "invalid type",
FromSqlError::Other(ref err) => err.description(),
}
}
#[cfg_attr(feature="clippy", allow(match_same_arms))]
fn cause(&self) -> Option<&Error> {
match *self {
FromSqlError::InvalidType => None,
FromSqlError::Other(ref err) => err.cause(),
}
}
}
pub type FromSqlResult<T> = Result<T, FromSqlError>;
pub trait FromSql: Sized {
fn column_result(value: ValueRef) -> FromSqlResult<Self>;
}
impl FromSql for i32 {
fn column_result(value: ValueRef) -> FromSqlResult<Self> {
i64::column_result(value).map(|i| i as i32)
}
}
impl FromSql for i64 {
fn column_result(value: ValueRef) -> FromSqlResult<Self> {
value.as_i64()
}
}
impl FromSql for f64 {
fn column_result(value: ValueRef) -> FromSqlResult<Self> {
match value {
ValueRef::Integer(i) => Ok(i as f64),
ValueRef::Real(f) => Ok(f),
_ => Err(FromSqlError::InvalidType),
}
}
}
impl FromSql for bool {
fn column_result(value: ValueRef) -> FromSqlResult<Self> {
i64::column_result(value).map(|i| match i {
0 => false,
_ => true,
})
}
}
impl FromSql for String {
fn column_result(value: ValueRef) -> FromSqlResult<Self> {
value.as_str().map(|s| s.to_string())
}
}
impl FromSql for Vec<u8> {
fn column_result(value: ValueRef) -> FromSqlResult<Self> {
value.as_blob().map(|b| b.to_vec())
}
}
impl<T: FromSql> FromSql for Option<T> {
fn column_result(value: ValueRef) -> FromSqlResult<Self> {
match value {
ValueRef::Null => Ok(None),
_ => FromSql::column_result(value).map(Some),
}
}
}
impl FromSql for Value {
fn column_result(value: ValueRef) -> FromSqlResult<Self> {
Ok(value.into())
}
}