Function exec_down

sea-orm-migration/src/migrator.rs:403–439

(manager: &SchemaManager<'_>, mut steps: Option<u32>)

}

async fn exec_down<M>(manager: &SchemaManager<'_>, mut steps: Option<u32>) -> Result<(), DbErr>
where
    M: MigratorTrait + ?Sized,
{
    let db = manager.get_connection();

    M::install(db).await?;

    if let Some(steps) = steps {
        info!("Rolling back {} applied migrations", steps);
    } else {
        info!("Rolling back all applied migrations");
    }

    let migrations = M::get_applied_migrations(db).await?.into_iter().rev();
    if migrations.len() == 0 {
        info!("No applied migrations");
    }
    for Migration { migration, .. } in migrations {
        if let Some(steps) = steps.as_mut() {
            if steps == &0 {
                break;
            }
            *steps -= 1;
        }
        info!("Rolling back migration '{}'", migration.name());
        migration.down(manager).await?;
        info!("Migration '{}' has been rollbacked", migration.name());
        seaql_migrations::Entity::delete_many()
            .filter(Expr::col(seaql_migrations::Column::Version).eq(migration.name()))
            .table_name(M::migration_table_name())
            .exec(db)
            .await?;
    }

    Ok(())
}

async fn query_tables<C>(db: &C) -> SelectStatement
where