Trait sqlm_postgres::SqlType
source · pub trait SqlType {
type Type;
// Provided method
fn query_literal<'a>(
sql: &'a Sql<'a, Primitive<Self::Type>, Self>,
conn: impl Connection + 'a,
) -> Pin<Box<dyn Future<Output = Result<Self, Error>> + Send + 'a>>
where Self: FromSqlOwned + ToSql + Send + Sync,
Self::Type: Send + Sync { ... }
}Expand description
A trait used to which Rust type a Postgres type is read into.
§Example
This can be useful to implement manually when e.g. reading a Postgres string column into an enum.
#[derive(Debug, Default, Clone, Copy)]
pub enum Role {
#[default]
User,
Admin,
}
impl sqlm_postgres::SqlType for Role {
type Type = String;
}
impl Role {
pub fn as_str(&self) -> &'static str {
match self {
Self::User => "user",
Self::Admin => "admin",
}
}
}
impl<'a> sqlm_postgres::FromSql<'a> for Role {
fn from_sql(
ty: &postgres_types::Type,
raw: &'a [u8],
) -> Result<Self, Box<dyn std::error::Error + Sync + Send>> {
use std::str::FromStr;
Ok(Role::from_str(<&str>::from_sql(ty, raw)?)?)
}
fn accepts(ty: &postgres_types::Type) -> bool {
<&str as sqlm_postgres::FromSql<'_>>::accepts(ty)
}
}
impl sqlm_postgres::ToSql for Role {
fn to_sql(
&self,
ty: &postgres_types::Type,
out: &mut bytes::BytesMut,
) -> Result<postgres_types::IsNull, Box<dyn std::error::Error + Sync + Send>>
where
Self: Sized,
{
<&str as sqlm_postgres::ToSql>::to_sql(&self.as_str(), ty, out)
}
fn accepts(ty: &postgres_types::Type) -> bool
where
Self: Sized,
{
<&str as sqlm_postgres::ToSql>::accepts(ty)
}
fn to_sql_checked(
&self,
ty: &postgres_types::Type,
out: &mut bytes::BytesMut,
) -> Result<postgres_types::IsNull, Box<dyn std::error::Error + Sync + Send>> {
<&str as sqlm_postgres::ToSql>::to_sql_checked(&self.as_str(), ty, out)
}
}
impl std::str::FromStr for Role {
type Err = UnknownRole;
fn from_str(s: &str) -> Result<Self, Self::Err> {
match s {
"user" => Ok(Role::User),
"admin" => Ok(Role::Admin),
s => Err(UnknownRole(s.to_string())),
}
}
}
#[derive(Debug)]
pub struct UnknownRole(String);
impl std::fmt::Display for UnknownRole {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
write!(f, "Unknown bevel lhs `{}`", self.0)
}
}
impl std::error::Error for UnknownRole {}