use serde::{Deserialize, Serialize}; use native_db::*; use native_db::native_model::{native_model, Model}; use once_cell::sync::Lazy; #[derive(Serialize, Deserialize, PartialEq, Debug)] #[native_model(id = 1, version = 1)] #[native_db] struct Item { #[primary_key] id: u32, #[secondary_key] name: String, } // Define the models // The lifetime of the models needs to be longer or equal to the lifetime of the database. // In many cases, it is simpler to use a static variable but it is not mandatory. static MODELS: Lazy<Models> = Lazy::new(|| { let mut models = Models::new(); models.define::<Item>().unwrap(); models }); fn main() -> Result<(), db_type::Error> { // Create a database in memory let mut db = Builder::new().create_in_memory(&MODELS)?; // Insert data (open a read-write transaction) let rw = db.rw_transaction()?; rw.insert(Item { id: 1, name: "red".to_string() })?; rw.insert(Item { id: 2, name: "green".to_string() })?; rw.insert(Item { id: 3, name: "blue".to_string() })?; rw.commit()?; // Open a read-only transaction let r = db.r_transaction()?; // Retrieve data with id=3  let retrieve_data: Item = r.get().primary(3_u32)?.unwrap(); println!("data id='3': {:?}", retrieve_data); // Iterate items with name starting with "red" for item in r.scan().secondary::<Item>(ItemKey::name)?.start_with("red")? { println!("data name=\"red\": {:?}", item); } // Remove data (open a read-write transaction) let rw = db.rw_transaction()?; rw.remove(retrieve_data)?; rw.commit()?; Ok(()) }