How to use JsonRawValue?

[nicksrandall]

I'm making a query (Postgres) in a REST endpoint handler that returns a single column that is a JSON value. I would like to return this JSON value as the response of the endpoint and avoid the cost of deserializing and re-serializing the value before it is sent. I'm assuming that that is what JsonRawValue is for, but I can't figure out how to use it.

Any help would be greatly appreciated!

[nicksrandall]

I finally figured it out:

// this is the value that the query returns (using query_as)
#[derive(Deserialize)]
struct QueryResponse {
    data: Box<sqlx::types::JsonRawValue>,
}

// custom impl of `FromRow`
impl FromRow<'_, PgRow> for QueryResponse {
    fn from_row(row: &PgRow) -> sqlx::Result<Self> {
        Ok(QueryResponse {
            data: to_raw_value::<&sqlx::types::JsonRawValue>(&row.get(0)).unwrap(),
        })
    }
}

// This is what the api returns.
#[derive(Serialize)]
struct APIResponse {
    data: Box<sqlx::types::JsonRawValue>,
   // other fields omitted for brevity. 
}