Upsert in Postgres not updating any fields

[jblachly]

I have a struct:

#[derive(Debug, Deserialize, Serialize, Insertable, AsChangeset)]
#[diesel(table_name = crate::schema::publication_poll_cache)]
pub struct PublicationPollCache {
    /// Option is ok for PK on insertable, but not queryable, structs
    pub id: Option<i32>,
    pub user_id: i32,
    pub source: PollSource,
    pub last_checked: chrono::naive::NaiveDateTime,
    pub last_results: serde_json::Value,
}

and I attempt to update the fields last_checked and last_results, however, despite "success" return from database, those fields are not updated.

Relevant code (note that the variable last_results is not used, as I am trying to set it to Null to prove that the database field gets updated; likewise the last_checked field is not updated to current time, either)

    let last_results = serde_json::to_value(csl).expect("Must convert");

    let cache_id: Option<i32> = ppc_dsl::publication_poll_cache
        .select(ppc_dsl::id)
        .filter(ppc_dsl::user_id.eq(user.id))
        .filter(ppc_dsl::source.eq(source.to_string()))
        .get_result::<i32>(connection)
        .optional()?;

    let cache_row = PublicationPollCache {
        id: cache_id,
        user_id: user.id,
        source,
        last_checked: chrono::Utc::now().naive_local(),
        // TODO revert below
        last_results: serde_json::Value::Null
    };
    tracing::trace!("cache_row to insert: {:?}", cache_row);
    // Upsert via ON CONFLICT (id) DO UPDATE SET id = EXCLUDED.id
    let _x = diesel::insert_into(ppc_dsl::publication_poll_cache)
        .values(&cache_row)
        .on_conflict(ppc_dsl::id)
        .do_update()
        .set(ppc_dsl::id.eq(excluded(ppc_dsl::id)))
        .execute(connection)?;

    tracing::debug!(user = user.email, "poll cache updated");

Any ideas where I am going wrong?

Is it the fact that I do not have Identifiable trait on the struct? Surely, I don't need to include every field in the set statement??? That sort of defeats the purpose of having an AsChangeset struct.

Diesel version: 2.2.1 (but I didn't see anything in the subsequent changelogs that addresses this)

Thanks to all in advance for pointers

[jblachly]

Asked and Answered:

Needing to specify ALL fields after a conflict is a postgres limitation; diesel supports using an AsChangeset struct in the .set ala:

.do_update().set(&cache_row)...