1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
|
use std::fmt;
use sqlx::{sqlite::Sqlite, SqliteConnection, Transaction};
pub trait Provider {
fn sequence(&mut self) -> Sequences;
}
impl<'c> Provider for Transaction<'c, Sqlite> {
fn sequence(&mut self) -> Sequences {
Sequences(self)
}
}
pub struct Sequences<'t>(&'t mut SqliteConnection);
impl<'c> Sequences<'c> {
pub async fn next(&mut self) -> Result<Sequence, sqlx::Error> {
let next = sqlx::query_scalar!(
r#"
update event_sequence
set last_value = last_value + 1
returning last_value as "next_value: Sequence"
"#,
)
.fetch_one(&mut *self.0)
.await?;
Ok(next)
}
pub async fn current(&mut self) -> Result<Sequence, sqlx::Error> {
let next = sqlx::query_scalar!(
r#"
select last_value as "last_value: Sequence"
from event_sequence
"#,
)
.fetch_one(&mut *self.0)
.await?;
Ok(next)
}
}
#[derive(
Clone,
Copy,
Debug,
Eq,
Ord,
PartialEq,
PartialOrd,
serde::Deserialize,
serde::Serialize,
sqlx::Type,
)]
#[serde(transparent)]
#[sqlx(transparent)]
pub struct Sequence(i64);
impl fmt::Display for Sequence {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
let Self(value) = self;
value.fmt(f)
}
}
|
