rustyroad 1.8.0

Rusty Road is a framework written in Rust that is based on Ruby on Rails. It is designed to provide the familiar conventions and ease of use of Ruby on Rails, while also taking advantage of the performance and efficiency of Rust.
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37

//! Primary key discovery for the backfill loop.

use crate::database::migrations::CustomMigrationError;
use crate::database::DatabaseConnection;
use sqlx::Row as _;

/// Reads the primary key columns of `table`, in key order.
const PRIMARY_KEY_SQL: &str = "SELECT a.attname \
     FROM pg_index i \
     JOIN pg_attribute a ON a.attrelid = i.indrelid AND a.attnum = ANY(i.indkey) \
     WHERE i.indrelid = $1::regclass AND i.indisprimary \
     ORDER BY array_position(i.indkey, a.attnum)";

/// Returns the primary key columns of `table`.
///
/// The backfill paginates over the primary key, so a table without one cannot be
/// backfilled in batches; that is reported rather than silently falling back to a
/// full-table update, which would hold locks for the duration.
pub(super) async fn primary_key(
    connection: &DatabaseConnection,
    table: &str,
) -> Result<Vec<String>, CustomMigrationError> {
    let DatabaseConnection::Pg(pool) = connection else {
        return Ok(Vec::new());
    };

    let rows = sqlx::query(PRIMARY_KEY_SQL)
        .bind(table)
        .fetch_all(pool.as_ref())
        .await
        .map_err(CustomMigrationError::SqlxError)?;

    Ok(rows
        .iter()
        .filter_map(|row| row.try_get::<String, _>("attname").ok())
        .collect())
}