impl IntoArguments for Arguments

[hxzhao527]

I have found these related issues/pull requests

relates to #3833

Description

When I want to make a generic create sql call, I find it won't compile as expected.

pub async fn upsert_download_event<'q, 'e, E>(
    executor: E,
    uuid: String,
    status: String,
) -> Result<(), sqlx::Error>
where
    E: Executor<'e>,
    E::Database: sqlx::Database,
    DateTime<Utc>: sqlx::Type< E::Database > + sqlx::Encode<'q, E::Database>,
    String: sqlx::Type< E::Database > + sqlx::Encode<'q, E::Database>
{
    let query = sqlx::query(
        r#"
        INSERT INTO m3u8_download_event (
            created_at,
            updated_at,
            uuid,
            status
        )
        VALUES ($1, $2, $3, $4)
        ON CONFLICT (uuid) DO UPDATE
        SET updated_at = EXCLUDED.updated_at,
            status = EXCLUDED.status
        "#,
    )
    .bind(Utc::now())
    .bind(Utc::now())
    .bind(uuid)
    .bind(status);

    query.execute(executor).await?;

    Ok(())
}

It will got

error[E0599]: the method `execute` exists for struct `Query<'_, <E as Executor<'e>>::Database, ...>`, but its trait bounds were not satisfied
   --> src/a.rs:232:11
    |
232 |     query.execute(executor).await?;
    |           ^^^^^^^ method cannot be called on `Query<'_, <E as Executor<'e>>::Database, ...>` due to unsatisfied trait bounds
    |
    = note: the following trait bounds were not satisfied:
            `<<E as Executor<'e>>::Database as sqlx::Database>::Arguments<'_>: IntoArguments<'_, <E as Executor<'e>>::Database>`

It is too strange that <<E as Executor<'e>>::Database as sqlx::Database>::Arguments<'_> doesn't impl IntoArguments<'_, <E as Executor<'e>>::Database>. (It's already Arguments)

I found that others have also encountered the same/similar issue in discord channel
https://discordapp.com/channels/665528275556106240/665528275556106243/1363047542996205579.

Prefered solution

like #3833

To avoid introducing breaking changes and without modifying the implementation of Query, we can add an implementation for Arguments.

Is this a breaking change? Why or why not?

struct which impl both Arguments and IntoArguments will conflict now.