the trait bound `i32: diesel::Expression` is not satisfied [E0277]

[fuyingfuying]

@sgrif
Another error. Please help me.
On ubuntu 15.10.

fuying@fuying-linux:~/rustprojs/simtraining$ cargo --version
cargo 0.11.0-nightly (b304305 2016-05-06)
fuying@fuying-linux:~/rustprojs/simtraining$ rustc --version
rustc 1.10.0-nightly (d91f8ab0f 2016-05-07)
fuying@fuying-linux:~/rustprojs/simtraining$ cargo build
   Compiling simtraining v0.1.0 (file:///home/fuying/rustprojs/simtraining)
src/dev.rs:7:23: 7:23 error: the trait bound `i32: diesel::Expression` is not satisfied [E0277]
error: internal compiler error: unexpected panic
note: the compiler unexpectedly panicked. this is a bug.
note: we would appreciate a bug report: https://github.com/rust-lang/rust/blob/master/CONTRIBUTING.md#bug-reports
thread 'rustc' panicked at 
'no annotations resulted from: 
Line { line_index: 6, annotations: [Annotation { start_col: 22, end_col: 22, is_primary: true, label: None }] }', 
../src/libsyntax/errors/snippet/mod.rs:495
note: Run with `RUST_BACKTRACE=1` for a backtrace.

error: Could not compile `simtraining`.

To learn more, run the command again with --verbose.

up.sql:

CREATE TABLE users (
    uid VARCHAR PRIMARY KEY,
    password VARCHAR NOT NULL,
    level INTEGER NOT NULL,
    realname VARCHAR NOT NULL,
    age INTEGER NOT NULL,
    sex VARCHAR NOT NULL
);
CREATE TABLE training_sessions (
  id SERIAL PRIMARY KEY,
  sec BIGINT NOT NULL,
  nsec INTEGER NOT NULL,
  name VARCHAR NOT NULL,
  xitong_id INTEGER NOT NULL,
  admin_uid VARCHAR NOT NULL,
  users_uid VARCHAR[] NOT NULL,
  actions_id INTEGER[] NOT NULL,
  mode VARCHAR NOT NULL,
  state VARCHAR NOT NULL,
  sec_duration BIGINT NOT NULL,
  nsec_duration INTEGER NOT NULL,
  score_op_order DOUBLE PRECISION NOT NULL,
  score_op_correct DOUBLE PRECISION NOT NULL,
  score_op_duration DOUBLE PRECISION NOT NULL,
  score DOUBLE PRECISION NOT NULL
);

CREATE TABLE training_actions (
  id SERIAL PRIMARY KEY,
  sec BIGINT NOT NULL,
  nsec INTEGER NOT NULL,
  name VARCHAR NOT NULL,
  session_id INTEGER NOT NULL,
  user_uid INTEGER NOT NULL,
  action_type VARCHAR NOT NULL,
  dev_uid VARCHAR NOT NULL,
  zhanwei_uid VARCHAR NOT NULL,
  sec_duration BIGINT NOT NULL,
  nsec_duration INTEGER NOT NULL,
  score_op_order DOUBLE PRECISION NOT NULL,
  score_op_correct DOUBLE PRECISION NOT NULL,
  score_op_duration DOUBLE PRECISION NOT NULL,
  score DOUBLE PRECISION NOT NULL
);

CREATE TABLE zhanweis (
  uid VARCHAR PRIMARY KEY,
  zhanwei_type VARCHAR NOT NULL,
  user_id VARCHAR
);

CREATE TABLE devs (
  uid VARCHAR PRIMARY KEY,
  id INTEGER NOT NULL,
  dev_type VARCHAR NOT NULL
);

dev.rs

use schema::*;
use diesel;
use diesel::prelude::*;
use diesel::pg::PgConnection;
use diesel::result::Error;
#[derive(PartialEq, Clone, Debug, Serialize, Deserialize, Queryable)]
#[changeset_for(devs)]
#[insertable_into(devs)]
pub struct Dev {
    pub uid: String,
    pub id: i32,
    pub dev_type: String,
}

impl Dev {
    pub fn new(uid: &str, id: i32, dev_type: &str) -> Dev {
        Dev {
            uid: uid.to_string(),
            id: id,
            dev_type: dev_type.to_string(),
        }
    }
    pub fn create(conn: &PgConnection, _dev: Dev) -> diesel::QueryResult<Dev> {
        let dev = _dev.clone();
        match devs::table.find(_dev.uid).first::<Dev>(conn) {
            Err(Error::NotFound) => {
                return ::diesel::insert(&dev)
                           .into(devs::table)
                           .get_result(conn);
            }
            Ok(_) => return Err(Error::DatabaseError("此用户名已存在".to_string())),
            Err(e) => return Err(e),
        }
    }
    pub fn show_all(conn: &PgConnection) -> diesel::QueryResult<Vec<Dev>> {
        devs::table.load::<Dev>(conn)
    }
    pub fn find_by_id(conn: &PgConnection, _uid: &str) -> diesel::QueryResult<Dev> {
        devs::table.find(_uid.to_string()).first::<Dev>(conn)
    }
    pub fn update(conn: &PgConnection, _uid: &str, data: &Dev) -> diesel::QueryResult<usize> {
        use ::schema::devs::dsl::*;
        diesel::update(devs.filter(uid.eq(_uid.to_string()))).set(data).execute(conn)
    }
    pub fn delete(conn: &PgConnection, _uid: &str) -> diesel::QueryResult<usize> {
        use ::schema::devs::dsl::*;
        diesel::delete(devs.filter(uid.eq(_uid.to_string()))).execute(conn)
    }
}

[fuyingfuying]

@sgrif Please help me! I've tried some methods, but no way to solve the error. Is it a bug of diesel or a bug of the nightly rust compiler???

[sgrif]

At the moment we don't support having columns on structs called id that isn't the primary key

[fuyingfuying]

@sgrif Ok, it works, thanks for your help.