the trait `FromSql` is not implemented for `DateTime`

Question

I'm getting the following error when trying to compile my rust diesel project despite the diesel docs showing that this trait is implemented

the trait bound DateTime<Utc>: FromSql<diesel::sql_types::Timestamptz, Pg> is not satisfied

My schema.rs

pub mod offers {
    diesel::table! {
        offers.offers (id) {
            id -> Int4,
            #[max_length = 255]
            offername -> Varchar,
            #[max_length = 255]
            offertypeid -> Nullable<Varchar>,
            startdate -> Nullable<Timestamptz>,
            enddate -> Nullable<Timestamptz>,
            frequency -> Nullable<Int4>,
            #[max_length = 255]
            createdby -> Nullable<Varchar>,
            createdAt -> Nullable<Timestamptz>
        }
    }
}

Here is my models.rs:

use diesel::prelude::*;
use chrono::{DateTime, Utc};
use crate::schema::offers::offers as offerTable;

#[derive(Queryable, Selectable)]
#[diesel(table_name = offerTable)]
#[diesel(check_for_backend(diesel::pg::Pg))]
pub struct Offer {
    pub id: i32,
    pub enddate: Option<DateTime<Utc>>,
    pub createdAt: Option<DateTime<Utc>>,
    pub createdby: Option<String>,
    pub frequency: Option<i32>,
    pub offername: String,
    pub startdate: Option<DateTime<Utc>> <--- ERROR FOR THIS LINE
}

In the docs for diesel here is shows that this mapping should work and I haven't been able to figure out why it's not working

@kmdreko Wow that was it. I had no idea you had to specifically enable that. Thank you very much. Solved. — G_McC4332, Jun 01 '23 at 15:13

kmdreko · Accepted Answer · 2023-06-01T17:47:18.353

You need to enable the "chrono" feature for the implementation for DateTime<UTC> from the chrono crate to be provided. This is shown as an annotation in the docs and is not enabled by default. You can read more about this feature and others in Diesel's crate feature flags section of the docs.

So your Cargo.toml should contain at least this:

[dependencies]
diesel = { version = "2.1.0", features = ["postgres", "chrono"] }

This goes for Diesel version 1.x as well.

the trait `FromSql` is not implemented for `DateTime`

1 Answers1