how to use postgres enum with diesel?

errors.md

the trait bound sql_enums::Status: diesel::Expression is not satisfied required because of the requirements on the impl of diesel::expression::AsExpression<sql_enums::Status> for sql_enums::StatusrustcE0277 models.rs(19, 17): Exact error occurred here

the trait bound sql_enums::Status: diesel::Expression is not satisfied required because of the requirements on the impl of diesel::Expression for &'insert sql_enums::Status required because of the requirements on the impl of diesel::expression::AsExpression<sql_enums::Status> for &'insert sql_enums::StatusrustcE0277 models.rs(19, 17): Exact error occurred here

the trait bound sql_enums::Status: diesel::Expression is not satisfied required because of the requirements on the impl of diesel::Expression for &sql_enums::Status required because of the requirements on the impl of diesel::expression::AsExpression<sql_enums::Status> for &sql_enums::StatusrustcE0277 models.rs(19, 17): Exact error occurred here

model.rs

use crate::schema::categories;
use sql_type::Status;




#[derive(Debug, Insertable)] // ⬅️ Insertable: An error occurred at this position  ⬇️
#[table_name = "categories"]
pub struct NewCategory {
    pub parent_id: Option<i64>,
    pub is_leaf: bool,
    pub level: i16,
    pub status: Status,
    pub name: String,
    pub code: i64,
    pub weight: i64,
}
      
 // Error Info:    
// >the trait bound `sql_enums::Status: diesel::Expression` is not satisfied
// required because of the requirements on the impl of `diesel::expression::AsExpression<sql_enums::Status>` for `sql_enums::Status`rustcE0277
// models.rs(19, 17): Exact error occurred here

// >the trait bound `sql_enums::Status: diesel::Expression` is not satisfied
// required because of the requirements on the impl of `diesel::Expression` for `&'insert sql_enums::Status`
// required because of the requirements on the impl of `diesel::expression::AsExpression<sql_enums::Status>` for `&'insert sql_enums::Status`rustcE0277
// models.rs(19, 17): Exact error occurred here

// > the trait bound `sql_enums::Status: diesel::Expression` is not satisfied
// required because of the requirements on the impl of `diesel::Expression` for `&sql_enums::Status`
// required because of the requirements on the impl of `diesel::expression::AsExpression<sql_enums::Status>` for `&sql_enums::Status`rustcE0277
// models.rs(19, 17): Exact error occurred here

#[derive(Debug, AsChangeset)] //  ⬅️ Insertable: An error occurred at this position ⬇️
#[table_name = "categories"]
pub struct UpdateCategory {
    pub parent_id: Option<i64>,
    pub is_leaf: Option<bool>,
    pub level: Option<i16>,
    pub status: Option<Status>,
    pub name: Option<String>,
    pub weight: Option<i64>,
}
      
// Error info:
// the trait bound `sql_enums::Status: diesel::AppearsOnTable<schema::categories::table>` is not satisfied
// required because of the requirements on the impl of `diesel::AppearsOnTable<schema::categories::table>` for `&'update sql_enums::Status`
// required because of the requirements on the impl of `diesel::query_builder::AsChangeset` for `diesel::expression::operators::Eq<schema::categories::columns::status, &'update sql_enums::Status>`rustcE0277
// models.rs(31, 17): Exact error occurred here
// the trait bound `sql_enums::Status: diesel::AppearsOnTable<schema::categories::table>` is not satisfied
// required because of the requirements on the impl of `diesel::AppearsOnTable<schema::categories::table>` for `&sql_enums::Status`
// required because of the requirements on the impl of `diesel::query_builder::AsChangeset` for `diesel::expression::operators::Eq<schema::categories::columns::status, &sql_enums::Status>`rustcE0277
// models.rs(31, 17): Exact error occurred here
// the trait bound `sql_enums::Status: diesel::AppearsOnTable<schema::categories::table>` is not satisfied
// required because of the requirements on the impl of `diesel::query_builder::AsChangeset` for `diesel::expression::operators::Eq<schema::categories::columns::status, sql_enums::Status>`rustcE0277
// models.rs(31, 17): Exact error occurred here

schema.rs

table! {
  use diesel::sql_types::*;
  use crate::sql_enums::*;

  categories (id) {
      id -> Int8,
      parent_id -> Nullable<Int8>,
      is_leaf -> Bool,
      level -> Int2,
      status -> Status,
      name -> Varchar,
      code -> Int8,
      weight -> Int8,
      created_at -> Timestamptz,
      updated_at -> Timestamptz,
  }
}

sql_type.rs

use diesel::backend::Backend;
use diesel::deserialize::{self, FromSql};
use diesel::pg::Pg;
use diesel::serialize::{self, IsNull, Output, ToSql};
use diesel_derive_enum::DbEnum;

use std::io::Write;

#[derive(SqlType)]
#[postgres(type_name = "Status")]
pub struct StatusType;

#[derive(Debug, AsExpression, FromSqlRow)]
#[sql_type = "StatusType"]
pub enum Status {
    Pending,
    Processing,
    Passed,
    Unpassed,
    Disabled,
    Deleted,
    Working,
    Resting,
}

impl ToSql<StatusType, Pg> for Status {
    fn to_sql<W: Write>(&self, out: &mut Output<W, Pg>) -> serialize::Result {
        let s = match *self {
            Status::Pending => out.write_all(b"pending")?,
            Status::Processing => out.write_all(b"processing")?,
            Status::Passed => out.write_all(b"passed")?,
            Status::Unpassed => out.write_all(b"unpassed")?,
            Status::Disabled => out.write_all(b"disabled")?,
            Status::Deleted => out.write_all(b"deleted")?,
            Status::Working => out.write_all(b"working")?,
            Status::Resting => out.write_all(b"resting")?,
        };
        <&str as ToSql<StatusType, Pg>>::to_sql(s, out)
        // Ok(IsNull::No)
    }
}

// pub trait FromSql<A, DB: Backend>: Sized {
///        See the trait documentation.
///        at the diesel 1.4.4, in current master that is changed to diesel::pg::PgValue wrapper
///        fn from_sql(bytes: Option<&DB::RawValue>) -> Result<Self>;
///}
impl FromSql<StatusType, Pg> for Status {
    fn from_sql(
        bytes: Option<&<Pg as Backend>::RawValue>,
    ) -> deserialize::Result<Self> {
        match bytes.as_bytes() {
            b"pending" => Ok(Status::Pending),
            b"processing" => Ok(Status::Processing),
            b"passed" => Ok(Status::Passed),
            b"unpassed" => Ok(Status::Unpassed),
            b"disabled" => Ok(Status::Disabled),
            b"deleted" => Ok(Status::Deleted),
            b"working" => Ok(Status::Working),
            b"resting" => Ok(Status::Resting),
            _ => Err("Unrecognized enum variant".into()),
        }
    }
}

pub mod exports {
    pub use super::StatusType as Status;
}

rust version:

❯ rustc -V
rustc 1.50.0 (cb75ad5db 2021-02-10)