Configuration

Rango is configured via rango.toml at the root of your project.

rango.toml

[database]
backend = "sqlite"   # "sqlite", "postgres", "mysql" or "mariadb"
# url is optional here — prefer DATABASE_URL env var for credentials

[models]
src = "src"          # directory to scan for #[derive(Model)] (a path given to `rango makemigrations` overrides it)

[migrations]
dir = "migrations"   # directory for generated SQL files

Database URL

The database URL is read from (in priority order):

--database-url CLI argument
DATABASE_URL environment variable
url field in rango.toml (local dev only — do not commit credentials)

rango migrate also reads MIGRATE_DATABASE_URL before all of these: see migrate.

# Recommended for production
export DATABASE_URL=postgres://user:password@host:5432/mydb

# For local dev
DATABASE_URL=sqlite://db.sqlite3 rango migrate

Backends

`backend`	URL format	Notes
`sqlite`	`sqlite://path/to/db.sqlite3`	In-memory: `sqlite::memory:`
`postgres`	`postgres://user:pass@host:5432/db`	Also accepts `postgresql://`
`mysql`	`mysql://user:pass@host:3306/db`	MySQL 8.0+
`mariadb`	`mariadb://user:pass@host:3306/db`	MariaDB 10.6+; same driver as `mysql`

When a command gets a database URL (-d or DATABASE_URL), the backend is taken from its scheme (postgres / postgresql, mysql / mariadb, sqlite), whatever backend says. backend is the fallback for a URL with another form, and decides which SQL makemigrations writes.

Table names

Tables are never prefixed. The table name is the #[model(table = "...")] value, or the snake_case of the struct name. rango makemigrations and the runtime use the same names.

[models] prefix was removed: makemigrations fails if it is still set. Use #[model(table = "...")] instead.

Connection pool (Postgres)

rango::connect_postgres(&config) reads its settings from DatabaseConfig:

#![allow(unused)]
fn main() {
let mut config = DatabaseConfig::from_env()?;
config.statement_timeout_ms = Some(5_000); // cancel queries running longer than 5 s
config.lock_timeout_ms = Some(2_000);      // give up waiting for a lock after 2 s
config.slow_query_threshold_ms = 200;      // WARN log for queries slower than 200 ms
let pool = rango::connect_postgres(&config).await?;
}

Field	Default	Notes
`max_connections` / `min_connections`	20 / 2
`connect_timeout`	10 s	Pool acquire timeout → `Error::Timeout`
`idle_timeout`	600 s
`max_lifetime`	1800 s	Recycles old connections
`test_before_acquire`	`false`	Saves a round-trip per acquire; enable behind proxies that drop idle connections
`statement_timeout_ms` / `lock_timeout_ms`	server default	Sent at connection startup (PgBouncer: add them to `ignore_startup_parameters`)
`slow_query_threshold_ms`	500

Queries are logged through tracing on the sqlx::query target: every query at DEBUG, slow ones at WARN. Only SQL text is logged, never bound values. SQLite uses the same logging with a fixed 500 ms threshold.