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This post is auto-generated from RSS feed The Rust Programming Language Forum - Latest topics. Source: I need help with trait worked with DB

I want to write a base trait for to work with DB objects and implement the default methods . My trait look like

trait Model {
    type Entity: FromRow<'static, PgRow> + Send + Unpin + Debug;

    fn table_name() -> &'static str;

    async fn get_by(
        column: &str,
        value: impl sqlx::Encode<'_, Postgres> + sqlx::Type<Postgres> + Send + Debug,
    ) -> Result<Option<Self::Entity>, Error> {
        let sql = format!(
            "SELECT * FROM {} WHERE {} = $1 LIMIT 1",
            Self::table_name(),
            column
        );

        let query = query_as::<Postgres, Self::Entity>(&sql).bind(value);

        let row: Option<Self::Entity> = query.fetch_optional(pool()).await?;
        Ok(row)
    }
}

I get error:

error[E0599]: no method named `fetch_optional` found for struct `QueryAs<'_, Postgres, <Self as Model>::Entity, PgArguments>` in the current scope
  --> src/db/db.rs:33:47
   |
33 |         let row: Option<Self::Entity> = query.fetch_optional(pool()).await?;
   |                                               ^^^^^^^^^^^^^^ method not found in `QueryAs<'_, Postgres, <Self as Model>::Entity, PgArguments>`
   |
   = note: the method was found for
           - `QueryAs<'q, DB, O, A>`

I thought that depends on with imports, but I'v imported all I need.

use sqlx::{
    Error, FromRow, Postgres,
    postgres::{PgArguments, PgPool, PgRow},
    prelude::*,
    query::QueryAs,
    query_as,
};
use std::fmt::Debug;

Can you help me to understand, why query doesn't have fetch_* methods?
P.S pool() returns &'static PgPool

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