1 //! Traits dealing with SQLite data types.
2 //!
3 //! SQLite uses a [dynamic type system](https://www.sqlite.org/datatype3.html). Implementations of
4 //! the [`ToSql`] and [`FromSql`] traits are provided for the basic types that
5 //! SQLite provides methods for:
6 //!
7 //! * Strings (`String` and `&str`)
8 //! * Blobs (`Vec<u8>` and `&[u8]`)
9 //! * Numbers
10 //!
11 //! The number situation is a little complicated due to the fact that all
12 //! numbers in SQLite are stored as `INTEGER` (`i64`) or `REAL` (`f64`).
13 //!
14 //! [`ToSql`] and [`FromSql`] are implemented for all primitive number types.
15 //! [`FromSql`] has different behaviour depending on the SQL and Rust types, and
16 //! the value.
17 //!
18 //! * `INTEGER` to integer: returns an
19 //!   [`Error::IntegralValueOutOfRange`](crate::Error::IntegralValueOutOfRange)
20 //!   error if the value does not fit in the Rust type.
21 //! * `REAL` to integer: always returns an
22 //!   [`Error::InvalidColumnType`](crate::Error::InvalidColumnType) error.
23 //! * `INTEGER` to float: casts using `as` operator. Never fails.
24 //! * `REAL` to float: casts using `as` operator. Never fails.
25 //!
26 //! [`ToSql`] always succeeds except when storing a `u64` or `usize` value that
27 //! cannot fit in an `INTEGER` (`i64`). Also note that SQLite ignores column
28 //! types, so if you store an `i64` in a column with type `REAL` it will be
29 //! stored as an `INTEGER`, not a `REAL`.
30 //!
31 //! If the `time` feature is enabled, implementations are
32 //! provided for `time::OffsetDateTime` that use the RFC 3339 date/time format,
33 //! `"%Y-%m-%dT%H:%M:%S.%fZ"`, to store time values as strings.  These values
34 //! can be parsed by SQLite's builtin
35 //! [datetime](https://www.sqlite.org/lang_datefunc.html) functions.  If you
36 //! want different storage for datetimes, you can use a newtype.
37 #![cfg_attr(
38     feature = "time",
39     doc = r##"
40 For example, to store datetimes as `i64`s counting the number of seconds since
41 the Unix epoch:
42 
43 ```
44 use rusqlite::types::{FromSql, FromSqlError, FromSqlResult, ToSql, ToSqlOutput, ValueRef};
45 use rusqlite::Result;
46 
47 pub struct DateTimeSql(pub time::OffsetDateTime);
48 
49 impl FromSql for DateTimeSql {
50     fn column_result(value: ValueRef) -> FromSqlResult<Self> {
51         i64::column_result(value).and_then(|as_i64| {
52             time::OffsetDateTime::from_unix_timestamp(as_i64)
53             .map(|odt| DateTimeSql(odt))
54             .map_err(|err| FromSqlError::Other(Box::new(err)))
55         })
56     }
57 }
58 
59 impl ToSql for DateTimeSql {
60     fn to_sql(&self) -> Result<ToSqlOutput> {
61         Ok(self.0.unix_timestamp().into())
62     }
63 }
64 ```
65 
66 "##
67 )]
68 //! [`ToSql`] and [`FromSql`] are also implemented for `Option<T>` where `T`
69 //! implements [`ToSql`] or [`FromSql`] for the cases where you want to know if
70 //! a value was NULL (which gets translated to `None`).
71 
72 pub use self::from_sql::{FromSql, FromSqlError, FromSqlResult};
73 pub use self::to_sql::{ToSql, ToSqlOutput};
74 pub use self::value::Value;
75 pub use self::value_ref::ValueRef;
76 
77 use std::fmt;
78 
79 #[cfg(feature = "chrono")]
80 #[cfg_attr(docsrs, doc(cfg(feature = "chrono")))]
81 mod chrono;
82 mod from_sql;
83 #[cfg(feature = "serde_json")]
84 #[cfg_attr(docsrs, doc(cfg(feature = "serde_json")))]
85 mod serde_json;
86 #[cfg(feature = "time")]
87 #[cfg_attr(docsrs, doc(cfg(feature = "time")))]
88 mod time;
89 mod to_sql;
90 #[cfg(feature = "url")]
91 #[cfg_attr(docsrs, doc(cfg(feature = "url")))]
92 mod url;
93 mod value;
94 mod value_ref;
95 
96 /// Empty struct that can be used to fill in a query parameter as `NULL`.
97 ///
98 /// ## Example
99 ///
100 /// ```rust,no_run
101 /// # use rusqlite::{Connection, Result};
102 /// # use rusqlite::types::{Null};
103 ///
104 /// fn insert_null(conn: &Connection) -> Result<usize> {
105 ///     conn.execute("INSERT INTO people (name) VALUES (?1)", [Null])
106 /// }
107 /// ```
108 #[derive(Copy, Clone)]
109 pub struct Null;
110 
111 /// SQLite data types.
112 /// See [Fundamental Datatypes](https://sqlite.org/c3ref/c_blob.html).
113 #[derive(Clone, Debug, PartialEq, Eq)]
114 pub enum Type {
115     /// NULL
116     Null,
117     /// 64-bit signed integer
118     Integer,
119     /// 64-bit IEEE floating point number
120     Real,
121     /// String
122     Text,
123     /// BLOB
124     Blob,
125 }
126 
127 impl fmt::Display for Type {
fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result128     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
129         match *self {
130             Type::Null => f.pad("Null"),
131             Type::Integer => f.pad("Integer"),
132             Type::Real => f.pad("Real"),
133             Type::Text => f.pad("Text"),
134             Type::Blob => f.pad("Blob"),
135         }
136     }
137 }
138 
139 #[cfg(test)]
140 mod test {
141     use super::Value;
142     use crate::{params, Connection, Error, Result, Statement};
143     use std::os::raw::{c_double, c_int};
144 
checked_memory_handle() -> Result<Connection>145     fn checked_memory_handle() -> Result<Connection> {
146         let db = Connection::open_in_memory()?;
147         db.execute_batch("CREATE TABLE foo (b BLOB, t TEXT, i INTEGER, f FLOAT, n)")?;
148         Ok(db)
149     }
150 
151     #[test]
test_blob() -> Result<()>152     fn test_blob() -> Result<()> {
153         let db = checked_memory_handle()?;
154 
155         let v1234 = vec![1u8, 2, 3, 4];
156         db.execute("INSERT INTO foo(b) VALUES (?1)", [&v1234])?;
157 
158         let v: Vec<u8> = db.one_column("SELECT b FROM foo")?;
159         assert_eq!(v, v1234);
160         Ok(())
161     }
162 
163     #[test]
test_empty_blob() -> Result<()>164     fn test_empty_blob() -> Result<()> {
165         let db = checked_memory_handle()?;
166 
167         let empty = vec![];
168         db.execute("INSERT INTO foo(b) VALUES (?1)", [&empty])?;
169 
170         let v: Vec<u8> = db.one_column("SELECT b FROM foo")?;
171         assert_eq!(v, empty);
172         Ok(())
173     }
174 
175     #[test]
test_str() -> Result<()>176     fn test_str() -> Result<()> {
177         let db = checked_memory_handle()?;
178 
179         let s = "hello, world!";
180         db.execute("INSERT INTO foo(t) VALUES (?1)", [&s])?;
181 
182         let from: String = db.one_column("SELECT t FROM foo")?;
183         assert_eq!(from, s);
184         Ok(())
185     }
186 
187     #[test]
test_string() -> Result<()>188     fn test_string() -> Result<()> {
189         let db = checked_memory_handle()?;
190 
191         let s = "hello, world!";
192         db.execute("INSERT INTO foo(t) VALUES (?1)", [s.to_owned()])?;
193 
194         let from: String = db.one_column("SELECT t FROM foo")?;
195         assert_eq!(from, s);
196         Ok(())
197     }
198 
199     #[test]
test_value() -> Result<()>200     fn test_value() -> Result<()> {
201         let db = checked_memory_handle()?;
202 
203         db.execute("INSERT INTO foo(i) VALUES (?1)", [Value::Integer(10)])?;
204 
205         assert_eq!(10i64, db.one_column::<i64>("SELECT i FROM foo")?);
206         Ok(())
207     }
208 
209     #[test]
test_option() -> Result<()>210     fn test_option() -> Result<()> {
211         let db = checked_memory_handle()?;
212 
213         let s = Some("hello, world!");
214         let b = Some(vec![1u8, 2, 3, 4]);
215 
216         db.execute("INSERT INTO foo(t) VALUES (?1)", [&s])?;
217         db.execute("INSERT INTO foo(b) VALUES (?1)", [&b])?;
218 
219         let mut stmt = db.prepare("SELECT t, b FROM foo ORDER BY ROWID ASC")?;
220         let mut rows = stmt.query([])?;
221 
222         {
223             let row1 = rows.next()?.unwrap();
224             let s1: Option<String> = row1.get_unwrap(0);
225             let b1: Option<Vec<u8>> = row1.get_unwrap(1);
226             assert_eq!(s.unwrap(), s1.unwrap());
227             assert!(b1.is_none());
228         }
229 
230         {
231             let row2 = rows.next()?.unwrap();
232             let s2: Option<String> = row2.get_unwrap(0);
233             let b2: Option<Vec<u8>> = row2.get_unwrap(1);
234             assert!(s2.is_none());
235             assert_eq!(b, b2);
236         }
237         Ok(())
238     }
239 
240     #[test]
241     #[allow(clippy::cognitive_complexity)]
test_mismatched_types() -> Result<()>242     fn test_mismatched_types() -> Result<()> {
243         fn is_invalid_column_type(err: Error) -> bool {
244             matches!(err, Error::InvalidColumnType(..))
245         }
246 
247         let db = checked_memory_handle()?;
248 
249         db.execute(
250             "INSERT INTO foo(b, t, i, f) VALUES (X'0102', 'text', 1, 1.5)",
251             [],
252         )?;
253 
254         let mut stmt = db.prepare("SELECT b, t, i, f, n FROM foo")?;
255         let mut rows = stmt.query([])?;
256 
257         let row = rows.next()?.unwrap();
258 
259         // check the correct types come back as expected
260         assert_eq!(vec![1, 2], row.get::<_, Vec<u8>>(0)?);
261         assert_eq!("text", row.get::<_, String>(1)?);
262         assert_eq!(1, row.get::<_, c_int>(2)?);
263         assert!((1.5 - row.get::<_, c_double>(3)?).abs() < f64::EPSILON);
264         assert_eq!(row.get::<_, Option<c_int>>(4)?, None);
265         assert_eq!(row.get::<_, Option<c_double>>(4)?, None);
266         assert_eq!(row.get::<_, Option<String>>(4)?, None);
267 
268         // check some invalid types
269 
270         // 0 is actually a blob (Vec<u8>)
271         assert!(is_invalid_column_type(row.get::<_, c_int>(0).unwrap_err()));
272         assert!(is_invalid_column_type(row.get::<_, c_int>(0).unwrap_err()));
273         assert!(is_invalid_column_type(row.get::<_, i64>(0).err().unwrap()));
274         assert!(is_invalid_column_type(
275             row.get::<_, c_double>(0).unwrap_err()
276         ));
277         assert!(is_invalid_column_type(row.get::<_, String>(0).unwrap_err()));
278         #[cfg(feature = "time")]
279         assert!(is_invalid_column_type(
280             row.get::<_, time::OffsetDateTime>(0).unwrap_err()
281         ));
282         assert!(is_invalid_column_type(
283             row.get::<_, Option<c_int>>(0).unwrap_err()
284         ));
285 
286         // 1 is actually a text (String)
287         assert!(is_invalid_column_type(row.get::<_, c_int>(1).unwrap_err()));
288         assert!(is_invalid_column_type(row.get::<_, i64>(1).err().unwrap()));
289         assert!(is_invalid_column_type(
290             row.get::<_, c_double>(1).unwrap_err()
291         ));
292         assert!(is_invalid_column_type(
293             row.get::<_, Vec<u8>>(1).unwrap_err()
294         ));
295         assert!(is_invalid_column_type(
296             row.get::<_, Option<c_int>>(1).unwrap_err()
297         ));
298 
299         // 2 is actually an integer
300         assert!(is_invalid_column_type(row.get::<_, String>(2).unwrap_err()));
301         assert!(is_invalid_column_type(
302             row.get::<_, Vec<u8>>(2).unwrap_err()
303         ));
304         assert!(is_invalid_column_type(
305             row.get::<_, Option<String>>(2).unwrap_err()
306         ));
307 
308         // 3 is actually a float (c_double)
309         assert!(is_invalid_column_type(row.get::<_, c_int>(3).unwrap_err()));
310         assert!(is_invalid_column_type(row.get::<_, i64>(3).err().unwrap()));
311         assert!(is_invalid_column_type(row.get::<_, String>(3).unwrap_err()));
312         assert!(is_invalid_column_type(
313             row.get::<_, Vec<u8>>(3).unwrap_err()
314         ));
315         assert!(is_invalid_column_type(
316             row.get::<_, Option<c_int>>(3).unwrap_err()
317         ));
318 
319         // 4 is actually NULL
320         assert!(is_invalid_column_type(row.get::<_, c_int>(4).unwrap_err()));
321         assert!(is_invalid_column_type(row.get::<_, i64>(4).err().unwrap()));
322         assert!(is_invalid_column_type(
323             row.get::<_, c_double>(4).unwrap_err()
324         ));
325         assert!(is_invalid_column_type(row.get::<_, String>(4).unwrap_err()));
326         assert!(is_invalid_column_type(
327             row.get::<_, Vec<u8>>(4).unwrap_err()
328         ));
329         #[cfg(feature = "time")]
330         assert!(is_invalid_column_type(
331             row.get::<_, time::OffsetDateTime>(4).unwrap_err()
332         ));
333         Ok(())
334     }
335 
336     #[test]
test_dynamic_type() -> Result<()>337     fn test_dynamic_type() -> Result<()> {
338         use super::Value;
339         let db = checked_memory_handle()?;
340 
341         db.execute(
342             "INSERT INTO foo(b, t, i, f) VALUES (X'0102', 'text', 1, 1.5)",
343             [],
344         )?;
345 
346         let mut stmt = db.prepare("SELECT b, t, i, f, n FROM foo")?;
347         let mut rows = stmt.query([])?;
348 
349         let row = rows.next()?.unwrap();
350         assert_eq!(Value::Blob(vec![1, 2]), row.get::<_, Value>(0)?);
351         assert_eq!(Value::Text(String::from("text")), row.get::<_, Value>(1)?);
352         assert_eq!(Value::Integer(1), row.get::<_, Value>(2)?);
353         match row.get::<_, Value>(3)? {
354             Value::Real(val) => assert!((1.5 - val).abs() < f64::EPSILON),
355             x => panic!("Invalid Value {:?}", x),
356         }
357         assert_eq!(Value::Null, row.get::<_, Value>(4)?);
358         Ok(())
359     }
360 
361     macro_rules! test_conversion {
362         ($db_etc:ident, $insert_value:expr, $get_type:ty,expect $expected_value:expr) => {
363             $db_etc.insert_statement.execute(params![$insert_value])?;
364             let res = $db_etc
365                 .query_statement
366                 .query_row([], |row| row.get::<_, $get_type>(0));
367             assert_eq!(res?, $expected_value);
368             $db_etc.delete_statement.execute([])?;
369         };
370         ($db_etc:ident, $insert_value:expr, $get_type:ty,expect_from_sql_error) => {
371             $db_etc.insert_statement.execute(params![$insert_value])?;
372             let res = $db_etc
373                 .query_statement
374                 .query_row([], |row| row.get::<_, $get_type>(0));
375             res.unwrap_err();
376             $db_etc.delete_statement.execute([])?;
377         };
378         ($db_etc:ident, $insert_value:expr, $get_type:ty,expect_to_sql_error) => {
379             $db_etc
380                 .insert_statement
381                 .execute(params![$insert_value])
382                 .unwrap_err();
383         };
384     }
385 
386     #[test]
test_numeric_conversions() -> Result<()>387     fn test_numeric_conversions() -> Result<()> {
388         #![allow(clippy::float_cmp)]
389 
390         // Test what happens when we store an f32 and retrieve an i32 etc.
391         let db = Connection::open_in_memory()?;
392         db.execute_batch("CREATE TABLE foo (x)")?;
393 
394         // SQLite actually ignores the column types, so we just need to test
395         // different numeric values.
396 
397         struct DbEtc<'conn> {
398             insert_statement: Statement<'conn>,
399             query_statement: Statement<'conn>,
400             delete_statement: Statement<'conn>,
401         }
402 
403         let mut db_etc = DbEtc {
404             insert_statement: db.prepare("INSERT INTO foo VALUES (?1)")?,
405             query_statement: db.prepare("SELECT x FROM foo")?,
406             delete_statement: db.prepare("DELETE FROM foo")?,
407         };
408 
409         // Basic non-converting test.
410         test_conversion!(db_etc, 0u8, u8, expect 0u8);
411 
412         // In-range integral conversions.
413         test_conversion!(db_etc, 100u8, i8, expect 100i8);
414         test_conversion!(db_etc, 200u8, u8, expect 200u8);
415         test_conversion!(db_etc, 100u16, i8, expect 100i8);
416         test_conversion!(db_etc, 200u16, u8, expect 200u8);
417         test_conversion!(db_etc, u32::MAX, u64, expect u32::MAX as u64);
418         test_conversion!(db_etc, i64::MIN, i64, expect i64::MIN);
419         test_conversion!(db_etc, i64::MAX, i64, expect i64::MAX);
420         test_conversion!(db_etc, i64::MAX, u64, expect i64::MAX as u64);
421         test_conversion!(db_etc, 100usize, usize, expect 100usize);
422         test_conversion!(db_etc, 100u64, u64, expect 100u64);
423         test_conversion!(db_etc, i64::MAX as u64, u64, expect i64::MAX as u64);
424 
425         // Out-of-range integral conversions.
426         test_conversion!(db_etc, 200u8, i8, expect_from_sql_error);
427         test_conversion!(db_etc, 400u16, i8, expect_from_sql_error);
428         test_conversion!(db_etc, 400u16, u8, expect_from_sql_error);
429         test_conversion!(db_etc, -1i8, u8, expect_from_sql_error);
430         test_conversion!(db_etc, i64::MIN, u64, expect_from_sql_error);
431         test_conversion!(db_etc, u64::MAX, i64, expect_to_sql_error);
432         test_conversion!(db_etc, u64::MAX, u64, expect_to_sql_error);
433         test_conversion!(db_etc, i64::MAX as u64 + 1, u64, expect_to_sql_error);
434 
435         // FromSql integer to float, always works.
436         test_conversion!(db_etc, i64::MIN, f32, expect i64::MIN as f32);
437         test_conversion!(db_etc, i64::MAX, f32, expect i64::MAX as f32);
438         test_conversion!(db_etc, i64::MIN, f64, expect i64::MIN as f64);
439         test_conversion!(db_etc, i64::MAX, f64, expect i64::MAX as f64);
440 
441         // FromSql float to int conversion, never works even if the actual value
442         // is an integer.
443         test_conversion!(db_etc, 0f64, i64, expect_from_sql_error);
444         Ok(())
445     }
446 }
447