A native PostgreSQL driver for Rust.

Documentation is available at http://www.rust-ci.org/sfackler/rust-postgres/doc/postgres/.

Rust-Postgres is a pure-Rust frontend for the popular PostgreSQL database. It exposes a high level interface in the vein of JDBC or Go's database/sql package.

extern crate postgres;
extern crate time;

use time::Timespec;

use postgres::{PostgresConnection, NoSsl};
use postgres::types::ToSql;

struct Person {
    id: i32,
    name: String,
    time_created: Timespec,
    data: Option<Vec<u8>>
}

fn main() {
    let conn = PostgresConnection::connect("postgres://postgres@localhost",
                                           &NoSsl).unwrap();

    conn.execute("CREATE TABLE person (
                    id              SERIAL PRIMARY KEY,
                    name            VARCHAR NOT NULL,
                    time_created    TIMESTAMP NOT NULL,
                    data            BYTEA
                  )", []).unwrap();
    let me = Person {
        id: 0,
        name: "Steven".to_string(),
        time_created: time::get_time(),
        data: None
    };
    conn.execute("INSERT INTO person (name, time_created, data)
                    VALUES ($1, $2, $3)",
                 [&me.name, &me.time_created, &me.data]).unwrap();

    let stmt = conn.prepare("SELECT id, name, time_created, data FROM person")
            .unwrap();
    for row in stmt.query([]).unwrap() {
        let person = Person {
            id: row.get(0u),
            name: row.get(1u),
            time_created: row.get(2u),
            data: row.get(3u)
        };
        println!("Found person {}", person.name);
    }
}

• Rust - Rust-Postgres is developed against the master branch of the Rust repository. It will most likely not build against the versioned releases on http://www.rust-lang.org.

• PostgreSQL 7.4 or later - Rust-Postgres speaks version 3 of the PostgreSQL protocol, which corresponds to versions 7.4 and later. If your version of Postgres was compiled in the last decade, you should be okay.

Connect to a Postgres server using the standard URI format:

let conn = try!(PostgresConnection::connect("postgres://user:pass@host:port/database?arg1=val1&arg2=val2",
                                            &NoSsl));

pass may be omitted if not needed. port defaults to 5432 and database defaults to the value of user if not specified. The driver supports trust, password, and md5 authentication.

Unix domain sockets can be used as well. The host portion of the URI should be set to the absolute path to the directory containing the socket file. Since / is a reserved character in URLs, the path should be URL encoded.

let conn = try!(PosgresConnection::connect("postgres://postgres@%2Frun%2Fpostgres", &NoSsl));

Paths which contain non-UTF8 characters can be handled in a different manner; see the documentation for details.

Prepared statements can have parameters, represented as $n where n is an index into the parameter array starting from 1:

let stmt = try!(conn.prepare("SELECT * FROM foo WHERE bar = $1 AND baz = $2"));

A prepared statement can be executed with the query and execute methods. Both methods take an array of parameters to bind to the query represented as &ToSql trait objects. execute returns the number of rows affected by the query (or 0 if not applicable):

let stmt = try!(conn.prepare("UPDATE foo SET bar = $1 WHERE baz = $2"));
let updates = try!(stmt.execute([&1i32, &"biz"]));
println!("{} rows were updated", updates);

query returns an iterator over the rows returned from the database. The fields in a row can be accessed either by their indices or their column names, though access by index is more efficient. Unlike statement parameters, result columns are zero-indexed.

let stmt = try!(conn.prepare("SELECT bar, baz FROM foo"));
for row in try!(stmt.query([])) {
    let bar: i32 = row.get(0u);
    let baz: String = row.get("baz");
    println!("bar: {}, baz: {}", bar, baz);
}

In addition, PostgresConnection has a utility execute method which is useful if a statement is only going to be executed once:

let updates = try!(conn.execute("UPDATE foo SET bar = $1 WHERE baz = $2",
                                [&1i32, &"biz"]));
println!("{} rows were updated", updates);

The transaction method will start a new transaction. It returns a PostgresTransaction object which has the functionality of a PostgresConnection as well as methods to control the result of the transaction:

let trans = try!(conn.transaction());
try!(trans.execute(...));
let stmt = try!(trans.prepare(...));

if the_coast_is_clear {
    trans.set_commit();
}

try!(trans.finish());

The transaction will be active until the PostgresTransaction object falls out of scope. A transaction will roll back by default. Nested transactions are supported via savepoints.

A very basic fixed-size connection pool is provided in the pool module. A single pool can be shared across tasks and get_connection will block until a connection is available.

let pool = try!(PostgresConnectionPool::new("postgres://postgres@localhost",
                                            NoSsl, 5));

for _ in range(0, 10) {
    let pool = pool.clone();
    spawn(proc() {
        let conn = pool.get_connection();
        conn.query(...).unwrap();
    })
}

Rust-Postgres enforces a strict correspondence between Rust types and Postgres types. The driver currently supports the following conversions:

More conversions can be defined by implementing the ToSql and FromSql traits.

Like Rust itself, Rust-Postgres is still in the early stages of development, so don't be surprised if APIs change and things break. If something's not working properly, file an issue or submit a pull request!