Database Connection

To obtain a database connection, use the Database interface:

let db: DatabaseConnection = Database::connect("protocol://username:password@host/database").await?;

protocol can be mysql:, postgres: or sqlite:.

host is usually localhost, a domain name or an IP address.

tip

If you can't get localhost to work, try putting in an IP address and port number, e.g. 127.0.0.1:3306 or even 192.168.x.x.

Under the hood, a sqlx::Pool is created and owned by DatabaseConnection.

Each time you call execute or query_one/all on it, a connection will be acquired and released from the pool.

Multiple queries will execute in parallel as you await on them.

Connection String

Here are some tips for database specific options:

MySQL

mysql://username:password@host/database

Postgres

Specify a schema

postgres://username:password@host/database?currentSchema=my_schema

SQLite

In memory

sqlite::memory:

Create file if not exists

sqlite://path/to/db.sqlite?mode=rwc

Read only

sqlite://path/to/db.sqlite?mode=ro

Connect Options

To configure the connection, use the ConnectOptions interface:

let mut opt = ConnectOptions::new("protocol://username:password@host/database");
opt.max_connections(100)
    .min_connections(5)
    .connect_timeout(Duration::from_secs(8))
    .acquire_timeout(Duration::from_secs(8))
    .idle_timeout(Duration::from_secs(8))
    .max_lifetime(Duration::from_secs(8))
    .sqlx_logging(true)
    .sqlx_logging_level(log::LevelFilter::Info)
    .set_schema_search_path("my_schema"); // Setting default PostgreSQL schema

let db = Database::connect(opt).await?;

Checking Connection is Valid

Checks if a connection to the database is still valid.

|db: DatabaseConnection| {
    assert!(db.ping().await.is_ok());
    db.clone().close().await;
    assert!(matches!(db.ping().await, Err(DbErr::ConnectionAcquire)));
}

Closing Connection

The connection will be automatically closed on drop. To close the connection explicitly, call the close method.

let db = Database::connect(url).await?;

// Closing connection here
db.close().await?;