Can't compile diesel app--what am I missing?

rust-output.txt

error[E0277]: the trait bound `i64: diesel::deserialize::FromSql<diesel::sql_types::Nullable<diesel::sql_types::BigInt>, _>` is not satisfied
  --> src/main.rs:32:10
   |
32 |         .load::<db::models::Device>(&connection)
   |          ^^^^ the trait `diesel::deserialize::FromSql<diesel::sql_types::Nullable<diesel::sql_types::BigInt>, _>` is not implemented for `i64`
   |
   = help: the following implementations were found:
             <i64 as diesel::deserialize::FromSql<diesel::sql_types::BigInt, DB>>

For future arrivals: I needed to use Option<i64> because my field was Nullable. Like this:

use super::schema::devices;
use diesel::sql_types::Nullable;

#[derive(Queryable)]
pub struct Device {
  pub device_id: i64,
  pub barcode: Option<i64>,
  pub device_type: i32,
}