¶Database

Feature-gated behind database. One Database handle spans SQLite, MySQL, and Postgres via sqlx's Any driver — the backend is chosen by the URL scheme. It lives in the GUI-free elyra-db crate so the CLI can use it too.

elyra = { version = "0.1", features = ["database"] }

¶Connecting

The easiest path is App::database, which connects lazily and binds a Database into the container:

App::new()
    .database("sqlite://app.db?mode=rwc")   // scheme picks the driver
    .commands(commands![list_todos]);

Resolve it in commands:

use elyra::{Database, Ctx};

#[command]
async fn count(ctx: Ctx) -> Result<i64, String> {
    let db = ctx.get::<Database>();
    let row = elyra::db::sqlx::query("SELECT COUNT(*) AS n FROM todos")
        .fetch_one(db.pool()).await.map_err(|e| e.to_string())?;
    Ok(elyra::db::sqlx::Row::try_get(&row, "n").map_err(|e| e.to_string())?)
}

¶API

• Database::connect(url).await — connect eagerly (async; for the CLI / setup).
• Database::connect_lazy(url) — build the pool without connecting; connections open on first use (sync; used by App::database).
• db.pool() — the underlying sqlx::AnyPool, for running queries.
• db.driver() — the detected Driver (Sqlite / MySql / Postgres).
• db.migrator(dir) — a Migrator sharing this pool.

¶Writing queries

sqlx is re-exported as elyra::db::sqlx, so app crates don't need a direct dependency:

use elyra::db::sqlx::{self, Row};

Placeholders differ per backend (? for sqlite/mysql, $1 for postgres); the Any driver does not translate them. For hand-written queries, mind the target driver — or use models, whose query builder renders placeholders per driver for you.

¶Testing status

SQLite is fully test-covered. MySQL and Postgres compile and are supported, but aren't server-tested in this repo.

¶Related

• Migrations · Models
• Configuration — [database]