datom 0.1.1-pre4

An open-source database inspired by Datomic.

// SPDX-FileCopyrightText: 2021 Lutris Engineering, Inc
// SPDX-License-Identifier: BlueOak-1.0.0 OR BSD-2-Clause-Patent
// SPDX-FileContributor: Piper McCorkle <piper@lutris.engineering>

Currently built on top of sled, a modern embedded database, and is only suitable for embedded usage. Future multi-peer support is planned.

If you aren't already familiar with Datomic, it might help to look over Datomic's excellent documentation. To the user, datom-rs functions extremely similarly to Datomic.

use datom::{backends::SledStorage, Connection, EntityResult, Transaction, Value, ID};

// Use the sled storage backend to create a temporary database
let storage = SledStorage::connect_temp()?;

// Create a connection from that backend
let conn = Connection::new(storage);

// Create an ID to use for the username attribute
let username = ID::new();
// Create an ID to use for the user's entity
let user = ID::new();

// Create a transaction setting the username attribute on the user
// entity to "pmc"
let mut tx = Transaction::new();
tx.add(user.into(), username.into(), "pmc".into());
// Execute the transaction using the connection
conn.transact(tx)?;

// Get a view of the database in the current point in time
let db = conn.db()?;
// Get the value of the username attribute on the user entity
if let EntityResult::Value(Value::String(u)) = db.entity(user.into())?.get(username.into())? {
println!("The user's username is {}.", u);
}
# assert_eq!(db.entity(user.into())?.get(username.into())?, EntityResult::Value("pmc".into()));
# Ok::<(), Box<dyn std::error::Error>>(())