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use std::{borrow::Cow, collections::HashSet, sync::LazyLock};
use tank::{Entity, Executor, Result, expr, stream::TryStreamExt};
use tokio::sync::Mutex;
static MUTEX: LazyLock<Mutex<()>> = LazyLock::new(|| Mutex::new(()));
#[derive(Entity)]
#[tank(schema = "army")]
pub struct Tank {
#[tank(primary_key)]
pub name: String,
pub country: Cow<'static, str>,
#[tank(name = "caliber")]
pub caliber_mm: u16,
#[tank(name = "speed")]
pub speed_kmh: f32,
pub is_operational: bool,
pub units_produced: Option<u32>,
}
pub async fn readme(connection: &mut impl Executor) -> Result<()> {
let _lock = MUTEX.lock();
let my_tank = Tank {
name: "Tiger I".into(),
country: "Germany".into(),
caliber_mm: 88,
speed_kmh: 45.4,
is_operational: false,
units_produced: Some(1_347),
};
/*
* CREATE SCHEMA IF NOT EXISTS "army";
* CREATE TABLE IF NOT EXISTS "army"."tank" (
* "name" VARCHAR PRIMARY KEY,
* "country" VARCHAR NOT NULL,
* "caliber" USMALLINT NOT NULL,
* "speed" FLOAT NOT NULL,
* "is_operational" BOOLEAN NOT NULL,
* "units_produced" UINTEGER);
*/
Tank::create_table(connection, true, true).await?;
/*
* INSERT INTO "army"."tank" ("name", "country", "caliber", "speed", "is_operational", "units_produced") VALUES
* ('Tiger I', 'Germany', 88, 45.4, false, 1347)
* ON CONFLICT ("name") DO UPDATE SET
* "country" = EXCLUDED."country",
* "caliber" = EXCLUDED."caliber",
* "speed" = EXCLUDED."speed",
* "is_operational" = EXCLUDED."is_operational",
* "units_produced" = EXCLUDED."units_produced";
*/
my_tank.save(connection).await?;
/*
* DuckDB uses the appender API. Other drivers generate an INSERT:
* INSERT INTO "army"."tank" ("name", "country", "caliber", "speed", "is_operational", "units_produced") VALUES
* ('T-34/85', 'Soviet Union', 85, 53.0, false, 49200),
* ('M1 Abrams', 'USA', 120, 72.0, true, NULL);
*/
Tank::insert_many(
connection,
&[
Tank {
name: "T-34/85".into(),
country: "Soviet Union".into(),
caliber_mm: 85,
speed_kmh: 53.0,
is_operational: false,
units_produced: Some(49_200),
},
Tank {
name: "M1 Abrams".into(),
country: "USA".into(),
caliber_mm: 120,
speed_kmh: 72.0,
is_operational: true,
units_produced: None,
},
],
)
.await?;
/*
* SELECT "name", "country", "caliber", "speed", "is_operational", "units_produced"
* FROM "army"."tank"
* WHERE "is_operational" = false
* LIMIT 1000;
*/
let tanks = Tank::find_many(connection, expr!(Tank::is_operational == false), Some(1000))
.try_collect::<Vec<_>>()
.await?;
assert_eq!(
tanks
.iter()
.map(|t| t.name.to_string())
.collect::<HashSet<_>>(),
HashSet::from_iter(["Tiger I".into(), "T-34/85".into()])
);
Ok(())
}