Errors I am getting when trying to use an enum with Diesel

diesel-errors.rs

> This is the `enum` I am trying write/read to the DB

#[derive(Clone, Copy)]
#[repr(i16)]
pub enum Kind {
    Technical = 1,
    Client = 2,
    Community = 3,
}

impl AsExpression<SmallInt> for Kind {
    type Expression = AsExprOf<i16, SmallInt>;

    fn as_expression(self) -> Self::Expression {
        AsExpression::<SmallInt>::as_expression(*self as i16)
    }
}

impl FromSql<SmallInt, Pg> for Kind {
    fn from_sql(bytes: Option<&[u8]>) -> Result<Self, Box<Error+Send+Sync>> {
        Ok(Kind::Technical)
    }
}

> it is part of this larger structure:

#[derive(Serialize, Clone)]
#[derive(Queryable, Insertable)]
#[table_name = "questions"]
pub struct Question {
    pub id: i32,
    pub phrase: String,
    pub kind: Kind,  # <-- This is where I embedd the enum
}

>  These are the erorrs I am getting now (selection, just the first few)

error[E0277]: the trait bound `questions::Kind: diesel::Expression` is not satisfied
  --> src/models.rs:25:21
   |
25 | #[derive(Queryable, Insertable)]
   |                     ^^^^^^^^^^ the trait `diesel::Expression` is not implemented for `questions::Kind`
   |
   = note: required because of the requirements on the impl of `diesel::Expression` for `&'insert questions::Kind`
   = note: required because of the requirements on the impl of `diesel::expression::AsExpression<diesel::types::Nullable<diesel::types::SmallInt>>` for `&'insert questions::Kind`
   = note: this error originates in a macro outside of the current crate

error[E0277]: the trait bound `&'insert models::Question: diesel::Insertable<schema::questions::table, DB>` is not satisfied
  --> src/models.rs:25:21
   |
25 | #[derive(Queryable, Insertable)]
   |                     ^^^^^^^^^^ the trait `diesel::Insertable<schema::questions::table, DB>` is not implemented for `&'insert models::Question`
   |
   = help: the following implementations were found:
             <&'insert models::Question as diesel::Insertable<schema::questions::table, DB>>
   = note: required by `diesel::Insertable`
   = note: this error originates in a macro outside of the current crate

error[E0277]: the trait bound `questions::Kind: diesel::Expression` is not satisfied
  --> src/models.rs:25:21
   |
25 | #[derive(Queryable, Insertable)]
   |                     ^^^^^^^^^^ the trait `diesel::Expression` is not implemented for `questions::Kind`
   |
   = note: required because of the requirements on the impl of `diesel::Expression` for `&'insert questions::Kind`
   = note: required because of the requirements on the impl of `diesel::expression::AsExpression<diesel::types::Nullable<diesel::types::SmallInt>>` for `&'insert questions::Kind`
   = note: this error originates in a macro outside of the current crate

error[E0277]: the trait bound `DB: diesel::backend::SupportsDefaultKeyword` is not satisfied
  --> src/models.rs:25:21
   |
25 | #[derive(Queryable, Insertable)]
   |                     ^^^^^^^^^^ the trait `diesel::backend::SupportsDefaultKeyword` is not implemented for `DB`
   |
   = help: consider adding a `where DB: diesel::backend::SupportsDefaultKeyword` bound
   = note: required because of the requirements on the impl of `diesel::insertable::InsertValues<DB>` for `(diesel::insertable::ColumnInsertValue<schema::questions::columns::id, diesel::expression::bound::Bound<diesel::types::Nullable<diesel::types::Integer>, &i32>>, diesel::insertable::ColumnInsertValue<schema::questions::columns::phrase, diesel::expression::bound::Bound<diesel::types::Nullable<diesel::types::Text>, &std::string::String>>, diesel::insertable::ColumnInsertValue<schema::questions::columns::kind, &'insert questions::Kind>)`
   = note: required by `diesel::insertable::InsertValues`
   = note: this error originates in a macro outside of the current crate