rusqlite/types/
from_sql.rs

1use super::{Value, ValueRef};
2use std::borrow::Cow;
3use std::error::Error;
4use std::fmt;
5use std::str::Utf8Error;
6
7/// Enum listing possible errors from [`FromSql`] trait.
8#[derive(Debug)]
9#[non_exhaustive]
10pub enum FromSqlError {
11    /// Error when an SQLite value is requested, but the type of the result
12    /// cannot be converted to the requested Rust type.
13    InvalidType,
14
15    /// Error when the i64 value returned by SQLite cannot be stored into the
16    /// requested type.
17    OutOfRange(i64),
18
19    /// Error converting a string to UTF-8.
20    Utf8Error(Utf8Error),
21
22    /// Error when the blob result returned by SQLite cannot be stored into the
23    /// requested type due to a size mismatch.
24    InvalidBlobSize {
25        /// The expected size of the blob.
26        expected_size: usize,
27        /// The actual size of the blob that was returned.
28        blob_size: usize,
29    },
30
31    /// An error case available for implementors of the [`FromSql`] trait.
32    Other(Box<dyn Error + Send + Sync + 'static>),
33}
34
35impl FromSqlError {
36    /// Converts an arbitrary error type to [`FromSqlError`].
37    ///
38    /// This is a convenience function that boxes and unsizes the error type. It's main purpose is
39    /// to be usable in the `map_err` method. So instead of
40    /// `result.map_err(|error| FromSqlError::Other(Box::new(error))` you can write
41    /// `result.map_err(FromSqlError::other)`.
42    pub fn other<E: Error + Send + Sync + 'static>(error: E) -> Self {
43        Self::Other(Box::new(error))
44    }
45}
46
47impl PartialEq for FromSqlError {
48    fn eq(&self, other: &Self) -> bool {
49        match (self, other) {
50            (Self::InvalidType, Self::InvalidType) => true,
51            (Self::OutOfRange(n1), Self::OutOfRange(n2)) => n1 == n2,
52            (Self::Utf8Error(u1), Self::Utf8Error(u2)) => u1 == u2,
53            (
54                Self::InvalidBlobSize {
55                    expected_size: es1,
56                    blob_size: bs1,
57                },
58                Self::InvalidBlobSize {
59                    expected_size: es2,
60                    blob_size: bs2,
61                },
62            ) => es1 == es2 && bs1 == bs2,
63            (..) => false,
64        }
65    }
66}
67
68impl fmt::Display for FromSqlError {
69    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
70        match *self {
71            Self::InvalidType => write!(f, "Invalid type"),
72            Self::OutOfRange(i) => write!(f, "Value {i} out of range"),
73            Self::Utf8Error(ref err) => err.fmt(f),
74            Self::InvalidBlobSize {
75                expected_size,
76                blob_size,
77            } => {
78                write!(
79                    f,
80                    "Cannot read {expected_size} byte value out of {blob_size} byte blob"
81                )
82            }
83            Self::Other(ref err) => err.fmt(f),
84        }
85    }
86}
87
88impl Error for FromSqlError {
89    fn source(&self) -> Option<&(dyn Error + 'static)> {
90        match self {
91            Self::Utf8Error(ref err) => Some(err),
92            Self::Other(ref err) => Some(&**err),
93            _ => None,
94        }
95    }
96}
97
98/// Result type for implementors of the [`FromSql`] trait.
99pub type FromSqlResult<T> = Result<T, FromSqlError>;
100
101/// A trait for types that can be created from a SQLite value.
102pub trait FromSql: Sized {
103    /// Converts SQLite value into Rust value.
104    fn column_result(value: ValueRef<'_>) -> FromSqlResult<Self>;
105}
106
107macro_rules! from_sql_integral(
108    ($t:ident) => (
109        impl FromSql for $t {
110            #[inline]
111            fn column_result(value: ValueRef<'_>) -> FromSqlResult<Self> {
112                let i = i64::column_result(value)?;
113                i.try_into().map_err(|_| FromSqlError::OutOfRange(i))
114            }
115        }
116    );
117    (non_zero $nz:ty, $z:ty) => (
118        impl FromSql for $nz {
119            #[inline]
120            fn column_result(value: ValueRef<'_>) -> FromSqlResult<Self> {
121                let i = <$z>::column_result(value)?;
122                <$nz>::new(i).ok_or(FromSqlError::OutOfRange(0))
123            }
124        }
125    )
126);
127
128from_sql_integral!(i8);
129from_sql_integral!(i16);
130from_sql_integral!(i32);
131// from_sql_integral!(i64); // Not needed because the native type is i64.
132from_sql_integral!(isize);
133from_sql_integral!(u8);
134from_sql_integral!(u16);
135from_sql_integral!(u32);
136#[cfg(feature = "fallible_uint")]
137from_sql_integral!(u64);
138#[cfg(feature = "fallible_uint")]
139from_sql_integral!(usize);
140
141from_sql_integral!(non_zero std::num::NonZeroIsize, isize);
142from_sql_integral!(non_zero std::num::NonZeroI8, i8);
143from_sql_integral!(non_zero std::num::NonZeroI16, i16);
144from_sql_integral!(non_zero std::num::NonZeroI32, i32);
145from_sql_integral!(non_zero std::num::NonZeroI64, i64);
146#[cfg(feature = "i128_blob")]
147from_sql_integral!(non_zero std::num::NonZeroI128, i128);
148
149#[cfg(feature = "fallible_uint")]
150from_sql_integral!(non_zero std::num::NonZeroUsize, usize);
151from_sql_integral!(non_zero std::num::NonZeroU8, u8);
152from_sql_integral!(non_zero std::num::NonZeroU16, u16);
153from_sql_integral!(non_zero std::num::NonZeroU32, u32);
154#[cfg(feature = "fallible_uint")]
155from_sql_integral!(non_zero std::num::NonZeroU64, u64);
156// std::num::NonZeroU128 is not supported since u128 isn't either
157
158impl FromSql for i64 {
159    #[inline]
160    fn column_result(value: ValueRef<'_>) -> FromSqlResult<Self> {
161        value.as_i64()
162    }
163}
164
165impl FromSql for f32 {
166    #[inline]
167    fn column_result(value: ValueRef<'_>) -> FromSqlResult<Self> {
168        match value {
169            ValueRef::Integer(i) => Ok(i as Self),
170            ValueRef::Real(f) => Ok(f as Self),
171            _ => Err(FromSqlError::InvalidType),
172        }
173    }
174}
175
176impl FromSql for f64 {
177    #[inline]
178    fn column_result(value: ValueRef<'_>) -> FromSqlResult<Self> {
179        match value {
180            ValueRef::Integer(i) => Ok(i as Self),
181            ValueRef::Real(f) => Ok(f),
182            _ => Err(FromSqlError::InvalidType),
183        }
184    }
185}
186
187impl FromSql for bool {
188    #[inline]
189    fn column_result(value: ValueRef<'_>) -> FromSqlResult<Self> {
190        i64::column_result(value).map(|i| i != 0)
191    }
192}
193
194impl FromSql for String {
195    #[inline]
196    fn column_result(value: ValueRef<'_>) -> FromSqlResult<Self> {
197        value.as_str().map(ToString::to_string)
198    }
199}
200
201impl FromSql for Box<str> {
202    #[inline]
203    fn column_result(value: ValueRef<'_>) -> FromSqlResult<Self> {
204        value.as_str().map(Into::into)
205    }
206}
207
208impl FromSql for std::rc::Rc<str> {
209    #[inline]
210    fn column_result(value: ValueRef<'_>) -> FromSqlResult<Self> {
211        value.as_str().map(Into::into)
212    }
213}
214
215impl FromSql for std::sync::Arc<str> {
216    #[inline]
217    fn column_result(value: ValueRef<'_>) -> FromSqlResult<Self> {
218        value.as_str().map(Into::into)
219    }
220}
221
222impl FromSql for Vec<u8> {
223    #[inline]
224    fn column_result(value: ValueRef<'_>) -> FromSqlResult<Self> {
225        value.as_blob().map(<[u8]>::to_vec)
226    }
227}
228
229impl FromSql for Box<[u8]> {
230    #[inline]
231    fn column_result(value: ValueRef<'_>) -> FromSqlResult<Self> {
232        value.as_blob().map(Box::<[u8]>::from)
233    }
234}
235
236impl FromSql for std::rc::Rc<[u8]> {
237    #[inline]
238    fn column_result(value: ValueRef<'_>) -> FromSqlResult<Self> {
239        value.as_blob().map(std::rc::Rc::<[u8]>::from)
240    }
241}
242
243impl FromSql for std::sync::Arc<[u8]> {
244    #[inline]
245    fn column_result(value: ValueRef<'_>) -> FromSqlResult<Self> {
246        value.as_blob().map(std::sync::Arc::<[u8]>::from)
247    }
248}
249
250impl<const N: usize> FromSql for [u8; N] {
251    #[inline]
252    fn column_result(value: ValueRef<'_>) -> FromSqlResult<Self> {
253        let slice = value.as_blob()?;
254        slice.try_into().map_err(|_| FromSqlError::InvalidBlobSize {
255            expected_size: N,
256            blob_size: slice.len(),
257        })
258    }
259}
260
261#[cfg(feature = "i128_blob")]
262impl FromSql for i128 {
263    #[inline]
264    fn column_result(value: ValueRef<'_>) -> FromSqlResult<Self> {
265        let bytes = <[u8; 16]>::column_result(value)?;
266        Ok(Self::from_be_bytes(bytes) ^ (1_i128 << 127))
267    }
268}
269
270#[cfg(feature = "uuid")]
271impl FromSql for uuid::Uuid {
272    #[inline]
273    fn column_result(value: ValueRef<'_>) -> FromSqlResult<Self> {
274        let bytes = <[u8; 16]>::column_result(value)?;
275        Ok(Self::from_u128(u128::from_be_bytes(bytes)))
276    }
277}
278
279impl<T: FromSql> FromSql for Option<T> {
280    #[inline]
281    fn column_result(value: ValueRef<'_>) -> FromSqlResult<Self> {
282        match value {
283            ValueRef::Null => Ok(None),
284            _ => FromSql::column_result(value).map(Some),
285        }
286    }
287}
288
289impl<T: ?Sized> FromSql for Cow<'_, T>
290where
291    T: ToOwned,
292    T::Owned: FromSql,
293{
294    #[inline]
295    fn column_result(value: ValueRef<'_>) -> FromSqlResult<Self> {
296        <T::Owned>::column_result(value).map(Cow::Owned)
297    }
298}
299
300impl FromSql for Value {
301    #[inline]
302    fn column_result(value: ValueRef<'_>) -> FromSqlResult<Self> {
303        value.try_into()
304    }
305}
306
307#[cfg(test)]
308mod test {
309    #[cfg(all(target_family = "wasm", target_os = "unknown"))]
310    use wasm_bindgen_test::wasm_bindgen_test as test;
311
312    use super::{FromSql, FromSqlError};
313    use crate::{Connection, Error, Result};
314    use std::borrow::Cow;
315    use std::rc::Rc;
316    use std::sync::Arc;
317
318    #[test]
319    fn test_integral_ranges() -> Result<()> {
320        let db = Connection::open_in_memory()?;
321
322        fn check_ranges<T>(db: &Connection, out_of_range: &[i64], in_range: &[i64])
323        where
324            T: Into<i64> + FromSql + std::fmt::Debug,
325        {
326            for n in out_of_range {
327                let err = db
328                    .query_row("SELECT ?1", [n], |r| r.get::<_, T>(0))
329                    .unwrap_err();
330                match err {
331                    Error::IntegralValueOutOfRange(_, value) => assert_eq!(*n, value),
332                    _ => panic!("unexpected error: {err}"),
333                }
334            }
335            for n in in_range {
336                assert_eq!(
337                    *n,
338                    db.query_row("SELECT ?1", [n], |r| r.get::<_, T>(0))
339                        .unwrap()
340                        .into()
341                );
342            }
343        }
344
345        check_ranges::<i8>(&db, &[-129, 128], &[-128, 0, 1, 127]);
346        check_ranges::<i16>(&db, &[-32769, 32768], &[-32768, -1, 0, 1, 32767]);
347        check_ranges::<i32>(
348            &db,
349            &[-2_147_483_649, 2_147_483_648],
350            &[-2_147_483_648, -1, 0, 1, 2_147_483_647],
351        );
352        check_ranges::<u8>(&db, &[-2, -1, 256], &[0, 1, 255]);
353        check_ranges::<u16>(&db, &[-2, -1, 65536], &[0, 1, 65535]);
354        check_ranges::<u32>(&db, &[-2, -1, 4_294_967_296], &[0, 1, 4_294_967_295]);
355        Ok(())
356    }
357
358    #[test]
359    fn test_nonzero_ranges() -> Result<()> {
360        let db = Connection::open_in_memory()?;
361
362        macro_rules! check_ranges {
363            ($nz:ty, $out_of_range:expr, $in_range:expr) => {
364                for &n in $out_of_range {
365                    assert_eq!(
366                        db.query_row("SELECT ?1", [n], |r| r.get::<_, $nz>(0)),
367                        Err(Error::IntegralValueOutOfRange(0, n)),
368                        "{}",
369                        std::any::type_name::<$nz>()
370                    );
371                }
372                for &n in $in_range {
373                    let non_zero = <$nz>::new(n).unwrap();
374                    assert_eq!(
375                        Ok(non_zero),
376                        db.query_row("SELECT ?1", [non_zero], |r| r.get::<_, $nz>(0))
377                    );
378                }
379            };
380        }
381
382        check_ranges!(std::num::NonZeroI8, &[0, -129, 128], &[-128, 1, 127]);
383        check_ranges!(
384            std::num::NonZeroI16,
385            &[0, -32769, 32768],
386            &[-32768, -1, 1, 32767]
387        );
388        check_ranges!(
389            std::num::NonZeroI32,
390            &[0, -2_147_483_649, 2_147_483_648],
391            &[-2_147_483_648, -1, 1, 2_147_483_647]
392        );
393        check_ranges!(
394            std::num::NonZeroI64,
395            &[0],
396            &[-2_147_483_648, -1, 1, 2_147_483_647, i64::MAX, i64::MIN]
397        );
398        check_ranges!(
399            std::num::NonZeroIsize,
400            &[0],
401            &[-2_147_483_648, -1, 1, 2_147_483_647]
402        );
403        check_ranges!(std::num::NonZeroU8, &[0, -2, -1, 256], &[1, 255]);
404        check_ranges!(std::num::NonZeroU16, &[0, -2, -1, 65536], &[1, 65535]);
405        check_ranges!(
406            std::num::NonZeroU32,
407            &[0, -2, -1, 4_294_967_296],
408            &[1, 4_294_967_295]
409        );
410        #[cfg(feature = "fallible_uint")]
411        check_ranges!(
412            std::num::NonZeroU64,
413            &[0, -2, -1, -4_294_967_296],
414            &[1, 4_294_967_295, i64::MAX as u64]
415        );
416        #[cfg(feature = "fallible_uint")]
417        check_ranges!(
418            std::num::NonZeroUsize,
419            &[0, -2, -1, -4_294_967_296],
420            &[1, 4_294_967_295]
421        );
422
423        Ok(())
424    }
425
426    #[test]
427    fn test_cow() -> Result<()> {
428        let db = Connection::open_in_memory()?;
429
430        assert_eq!(
431            db.query_row("SELECT 'this is a string'", [], |r| r
432                .get::<_, Cow<'_, str>>(0)),
433            Ok(Cow::Borrowed("this is a string")),
434        );
435        assert_eq!(
436            db.query_row("SELECT x'09ab20fdee87'", [], |r| r
437                .get::<_, Cow<'_, [u8]>>(0)),
438            Ok(Cow::Owned(vec![0x09, 0xab, 0x20, 0xfd, 0xee, 0x87])),
439        );
440        assert_eq!(
441            db.query_row("SELECT 24.5", [], |r| r.get::<_, Cow<'_, f32>>(0),),
442            Ok(Cow::Borrowed(&24.5)),
443        );
444
445        Ok(())
446    }
447
448    #[test]
449    fn test_heap_slice() -> Result<()> {
450        let db = Connection::open_in_memory()?;
451
452        assert_eq!(
453            db.query_row("SELECT 'text'", [], |r| r.get::<_, Box<str>>(0)),
454            Ok(Box::from("text")),
455        );
456        assert_eq!(
457            db.query_row("SELECT 'Some string slice!'", [], |r| r
458                .get::<_, Rc<str>>(0)),
459            Ok(Rc::from("Some string slice!")),
460        );
461        assert_eq!(
462            db.query_row("SELECT x'012366779988fedc'", [], |r| r
463                .get::<_, Rc<[u8]>>(0)),
464            Ok(Rc::from(b"\x01\x23\x66\x77\x99\x88\xfe\xdc".as_slice())),
465        );
466
467        assert_eq!(
468            db.query_row(
469                "SELECT x'6120737472696e672043414e206265206120626c6f62'",
470                [],
471                |r| r.get::<_, Box<[u8]>>(0)
472            ),
473            Ok(b"a string CAN be a blob".to_vec().into_boxed_slice()),
474        );
475        assert_eq!(
476            db.query_row("SELECT 'This is inside an Arc.'", [], |r| r
477                .get::<_, Arc<str>>(0)),
478            Ok(Arc::from("This is inside an Arc.")),
479        );
480        assert_eq!(
481            db.query_row("SELECT x'afd374'", [], |r| r.get::<_, Arc<[u8]>>(0),),
482            Ok(Arc::from(b"\xaf\xd3\x74".as_slice())),
483        );
484
485        Ok(())
486    }
487
488    #[test]
489    fn from_sql_error() {
490        use std::error::Error as _;
491        assert_ne!(FromSqlError::InvalidType, FromSqlError::OutOfRange(0));
492        assert_ne!(FromSqlError::OutOfRange(0), FromSqlError::OutOfRange(1));
493        assert_ne!(
494            FromSqlError::InvalidBlobSize {
495                expected_size: 0,
496                blob_size: 0
497            },
498            FromSqlError::InvalidBlobSize {
499                expected_size: 0,
500                blob_size: 1
501            }
502        );
503        assert!(FromSqlError::InvalidType.source().is_none());
504        let err = std::io::Error::from(std::io::ErrorKind::UnexpectedEof);
505        assert!(FromSqlError::Other(Box::new(err)).source().is_some());
506    }
507}
rusqlite/types/from_sql.rs

rusqlite/types/
from_sql.rs
