db_derive/
error.rs

1use std::{convert::Infallible, error, fmt};
2
3#[derive(Debug)]
4pub enum Error {
5    R2D2(r2d2::Error),
6
7    PostgreSQL(postgres::Error),
8    SQLite(rusqlite::Error),
9
10    NoSqlQueryProvided,
11    QueryReturnedNoRows,
12    MismatchedColumnCount,
13}
14
15impl fmt::Display for Error {
16    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
17        match self {
18            Error::R2D2(err) => write!(f, "{}", err),
19
20            Error::PostgreSQL(err) => write!(f, "{}", err),
21            Error::SQLite(err) => write!(f, "{}", err),
22
23            Error::NoSqlQueryProvided => write!(
24                f,
25                "a sql query was not given to the type, this should not happen"
26            ),
27            Error::QueryReturnedNoRows => write!(f, "a sql query returned no rows"),
28            Error::MismatchedColumnCount => write!(
29                f,
30                "the given type and the returning query do not have the same amount of columns"
31            ),
32        }
33    }
34}
35
36impl error::Error for Error {
37    fn source(&self) -> Option<&(dyn error::Error + 'static)> {
38        match self {
39            Error::R2D2(err) => Some(err),
40
41            Error::PostgreSQL(err) => Some(err),
42            Error::SQLite(err) => Some(err),
43
44            Error::NoSqlQueryProvided => None,
45            Error::QueryReturnedNoRows => None,
46            Error::MismatchedColumnCount => None,
47        }
48    }
49}
50
51impl From<r2d2::Error> for Error {
52    fn from(err: r2d2::Error) -> Error {
53        Error::R2D2(err)
54    }
55}
56
57impl From<postgres::Error> for Error {
58    fn from(err: postgres::Error) -> Error {
59        Error::PostgreSQL(err)
60    }
61}
62
63impl From<rusqlite::Error> for Error {
64    fn from(err: rusqlite::Error) -> Error {
65        Error::SQLite(err)
66    }
67}
68
69impl From<Infallible> for Error {
70    fn from(_: Infallible) -> Self {
71        unreachable!()
72    }
73}
74
75pub trait OptionalExtension<T> {
76    fn optional(self) -> Result<Option<T>, Error>;
77}
78
79impl<T> OptionalExtension<T> for Result<T, Error> {
80    fn optional(self) -> Result<Option<T>, Error> {
81        match self {
82            Ok(value) => Ok(Some(value)),
83            Err(Error::QueryReturnedNoRows) => Ok(None),
84            Err(e) => Err(e),
85        }
86    }
87}
db_derive/error.rs

db_derive/
error.rs
