second reply.

Going over both error messages again, found this: https://stackoverflow.com/questions/70389667/rust-diesel-method-filter-exists-for-schema-table-but-its-trait-bounds-were-n

seems adding:

use diesel::prelude::*;

Might be helping. This compiles now:

    site_aggregates::table.filter(site_aggregates::site_id.eq(1)).first::<Self>(conn).await

   --> crates/db_schema/src/aggregates/site_aggregates.rs:12:35
    |
12  |     site_aggregates::dsl::site_id.eq(1).first::<Self>(conn).await
    |                                   ^^ `schema::site_aggregates::columns::site_id` is not an iterator
    |
   ::: crates/db_schema/src/schema.rs:817:9
    |
817 |         site_id -> Int4,
    |         -------
    |         |
    |         method `eq` not found for this struct
    |         doesn't satisfy `_: Iterator`
    |
    = note: the following trait bounds were not satisfied:
            `schema::site_aggregates::columns::site_id: Iterator`
            which is required by `&mut schema::site_aggregates::columns::site_id: Iterator`