はじめに
RustでPostgreSQLを使いたいです。PostgreSQLには様々な型があるので、Rustでそれに合った型で受け取りたいです。
以前RustとPostgreSQLで色々な型をやりとりしてみた(postgres 0.17対応)という記事を書きましたが、これの修正版になります。
以前との違いは以下のようになります。
- Rustのcrateであるpostgresからtokio-postgresに変更し、async/awaitにした
- PostgreSQLのNUMERIC型に対応
サポートされている型
tokio_postgresのドキュメントにサポートされる型が記述されています。
しかにここにはNUMERIC型の記述がありません。結構使われる重要な型だと思うのですが・・・
RustでPostgreSQLの型をサポートするには、tokio_postgres::types::FromSqlとtokio_postgres::types::ToSqlを実装すれば良いです。
rust_decimalがfeaturesでサポートしているので、これを使います。
プログラム
Cargo.toml
[package]
name = "playground"
version = "0.1.0"
edition = "2021"
# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
[dependencies]
bit-vec = "^0.6"
chrono = "^0.4"
eui48 = "^1.1"
geo-types = "^0.7"
deadpool-postgres = "^0.10"
rust_decimal = { version = "^1.23", features = ["db-tokio-postgres"] }
serde_json = "^1.0"
uuid = { version = "^0.8", features = ["serde", "v4"] }
tokio = { version = "1", features = ["full"] }
[dependencies.tokio-postgres]
version = "^0.7.5"
features = [
"with-bit-vec-0_6",
"with-chrono-0_4",
"with-eui48-1",
"with-geo-types-0_7",
"with-serde_json-1",
"with-uuid-0_8",
]
main.rs
use bit_vec::BitVec;
use chrono::prelude::*;
use deadpool_postgres::{
Manager,
ManagerConfig,
Pool,
RecyclingMethod,
tokio_postgres::{
Config,
NoTls
}
};
use eui48::{MacAddress, Eui48};
use geo_types::{
Coordinate,
Point,
Rect,
LineString,
};
use rust_decimal::Decimal;
use serde_json::Value;
use std::{
collections::{
HashMap,
},
net::{
IpAddr,
Ipv4Addr,
},
str::FromStr,
time::{
SystemTime,
},
};
use uuid::Uuid;
#[derive(Debug, PartialEq)]
struct Data {
bool_val: bool,
bool_array_val: Vec<bool>,
bool_option_some_val: Option<bool>,
bool_option_none_val: Option<bool>,
char_val: i8,
smallint_val: i16,
int_val: i32,
oid_val: u32,
bigint_val: i64,
real_val: f32,
double_val: f64,
text_val: String,
bytes_val: Vec<u8>,
hstore_val: HashMap<String, Option<String>>,
system_time_val: SystemTime,
inet_val: IpAddr,
timestamp_val: NaiveDateTime,
timestamptz_val: DateTime<Utc>,
date_val: NaiveDate,
time_val: NaiveTime,
macaddr_val: MacAddress,
point_val: Point<f64>,
box_val: Rect<f64>,
path_val: LineString<f64>,
jsonb_val: Value,
uuid_val: Uuid,
varbit_val: BitVec,
decimal_val: Decimal,
}
fn make_pool() -> Pool {
let mut pg_config = Config::new();
pg_config.host("db");
pg_config.user("user");
pg_config.password("pass");
pg_config.dbname("web");
let mgr_config = ManagerConfig {
recycling_method: RecyclingMethod::Fast
};
let mgr = Manager::from_config(pg_config, NoTls, mgr_config);
let pool = Pool::builder(mgr).max_size(16).build().unwrap();
pool
}
#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
let pool = make_pool();
let client = pool.get().await.unwrap();
let sql = r#"
SELECT
$1::BOOL AS bool_val
,$2::BOOL[] AS bool_array_val
,$3::BOOL AS bool_option_some_val
,$4::BOOL AS bool_option_none_val
,$5::"char" AS char_val
,$6::SMALLINT AS smallint_val
,$7::INT AS int_val
,$8::OID AS oid_val
,$9::BIGINT AS bigint_val
,$10::REAL AS real_val
,$11::DOUBLE PRECISION AS double_val
,$12::TEXT AS text_val
,$13::BYTEA AS bytes_val
,$14::HSTORE AS hstore_val
,$15::TIMESTAMPTZ AS system_time_val
,$16::INET AS inet_val
,$17::TIMESTAMP AS timestamp_val
,$18::TIMESTAMPTZ AS timestamptz_val
,$19::DATE AS date_val
,$20::TIME AS time_val
,$21::MACADDR AS macaddr_val
,$22::POINT AS point_val
,$23::BOX AS box_val
,$24::PATH AS path_val
,$25::JSONB AS jsonb_val
,$26::UUID AS uuid_val
,$27::VARBIT AS varbit_val
,$28::NUMERIC AS decimal_val
"#;
let stmt = client.prepare_cached(sql).await?;
let data = Data {
bool_val: true,
bool_array_val: vec![true, false],
bool_option_some_val: Some(true),
bool_option_none_val: None,
char_val: 1,
smallint_val: 2,
int_val: 3,
oid_val: 4,
bigint_val: 5,
real_val: 6.1,
double_val: 7.1,
text_val: "予定表〜①ﾊﾝｶｸだ".to_string(),
bytes_val: vec![240, 159, 146, 150],
hstore_val: {
let mut hstore_val = HashMap::new();
hstore_val.insert("key".to_string(), Some("value".to_string()));
hstore_val
},
system_time_val: SystemTime::UNIX_EPOCH, // SystemTime::now()は精度の差で一致しないが使える。
inet_val: IpAddr::V4(Ipv4Addr::new(127, 0, 0, 1)),
timestamp_val: NaiveDate::from_ymd(2001, 2, 3).and_hms(4, 5, 6),
timestamptz_val: Utc.ymd(2001, 2, 3).and_hms_milli(4, 5, 6, 7),
date_val: NaiveDate::from_ymd(2002, 3, 4),
time_val: NaiveTime::from_hms_milli(8, 59, 59, 100),
macaddr_val: {
let eui: Eui48 = [ 0x12, 0x34, 0x56, 0xAB, 0xCD, 0xEF ];
MacAddress::new( eui )
},
point_val: Point::new(1.234, 2.345),
box_val: Rect::new(
Coordinate { x: 0., y: 0. },
Coordinate { x: 10., y: 20. },
),
path_val: LineString(vec![
Coordinate { x: 0., y: 0. },
Coordinate { x: 10., y: 20. },]),
jsonb_val: {
let json_data = r#"{
"name" : "予定表〜①ﾊﾝｶｸだ",
"age" : 92233720368547758070
}"#;
serde_json::from_str(json_data).unwrap()
},
uuid_val: Uuid::new_v4(),
varbit_val: {
let mut varbit_val = BitVec::from_elem(10, false);
varbit_val.set(2, true);
varbit_val
},
decimal_val: Decimal::from_str("1.1").unwrap(),
};
let rows = client.query(&stmt, &[
&data.bool_val,
&data.bool_array_val,
&data.bool_option_some_val,
&data.bool_option_none_val,
&data.char_val,
&data.smallint_val,
&data.int_val,
&data.oid_val,
&data.bigint_val,
&data.real_val,
&data.double_val,
&data.text_val,
&data.bytes_val,
&data.hstore_val,
&data.system_time_val,
&data.inet_val,
&data.timestamp_val,
&data.timestamptz_val,
&data.date_val,
&data.time_val,
&data.macaddr_val,
&data.point_val,
&data.box_val,
&data.path_val,
&data.jsonb_val,
&data.uuid_val,
&data.varbit_val,
&data.decimal_val,
]).await?;
let row = rows.get(0).unwrap();
let res = Data {
bool_val: row.get("bool_val"),
bool_array_val: row.get("bool_array_val"),
bool_option_some_val: row.get("bool_option_some_val"),
bool_option_none_val: row.get("bool_option_none_val"),
char_val: row.get("char_val"),
smallint_val: row.get("smallint_val"),
int_val: row.get("int_val"),
oid_val: row.get("oid_val"),
bigint_val: row.get("bigint_val"),
real_val: row.get("real_val"),
double_val: row.get("double_val"),
text_val: row.get("text_val"),
bytes_val: row.get("bytes_val"),
hstore_val: row.get("hstore_val"),
system_time_val: row.get("system_time_val"),
inet_val: row.get("inet_val"),
timestamp_val: row.get("timestamp_val"),
timestamptz_val: row.get("timestamptz_val"),
date_val: row.get("date_val"),
time_val: row.get("time_val"),
macaddr_val: row.get("macaddr_val"),
point_val: row.get("point_val"),
box_val: row.get("box_val"),
path_val: row.get("path_val"),
jsonb_val: row.get("jsonb_val"),
uuid_val: row.get("uuid_val"),
varbit_val: row.get("varbit_val"),
decimal_val: row.get("decimal_val"),
};
assert_eq!(data, res);
println!("{:?}", data);
Ok(())
}