rusqlite/types/
serde_json.rs

1//! [`ToSql`] and [`FromSql`] implementation for JSON `Value`.
2
3use serde_json::{Number, Value};
4
5use crate::types::{FromSql, FromSqlError, FromSqlResult, ToSql, ToSqlOutput, ValueRef};
6use crate::{Error, Result};
7
8/// Serialize JSON `Value` to text:
9///
10///
11/// | JSON   | SQLite    |
12/// |----------|---------|
13/// | Null     | NULL    |
14/// | Bool     | 'true' / 'false' |
15/// | Number   | INT or REAL except u64 |
16/// | _ | TEXT |
17impl ToSql for Value {
18    #[inline]
19    fn to_sql(&self) -> Result<ToSqlOutput<'_>> {
20        match self {
21            Value::Null => Ok(ToSqlOutput::Borrowed(ValueRef::Null)),
22            Value::Number(n) if n.is_i64() => Ok(ToSqlOutput::from(n.as_i64().unwrap())),
23            Value::Number(n) if n.is_f64() => Ok(ToSqlOutput::from(n.as_f64().unwrap())),
24            _ => serde_json::to_string(self)
25                .map(ToSqlOutput::from)
26                .map_err(|err| Error::ToSqlConversionFailure(err.into())),
27        }
28    }
29}
30
31/// Deserialize SQLite value to JSON `Value`:
32///
33/// | SQLite   | JSON    |
34/// |----------|---------|
35/// | NULL     | Null    |
36/// | 'null'   | Null    |
37/// | 'true'   | Bool    |
38/// | 1        | Number  |
39/// | 0.1      | Number  |
40/// | '"text"' | String  |
41/// | 'text'   | _Error_ |
42/// | '[0, 1]' | Array   |
43/// | '{"x": 1}' | Object  |
44impl FromSql for Value {
45    #[inline]
46    fn column_result(value: ValueRef<'_>) -> FromSqlResult<Self> {
47        match value {
48            ValueRef::Text(s) => serde_json::from_slice(s), // KO for b"text"
49            ValueRef::Blob(b) => serde_json::from_slice(b),
50            ValueRef::Integer(i) => Ok(Value::Number(Number::from(i))),
51            ValueRef::Real(f) => {
52                match Number::from_f64(f) {
53                    Some(n) => Ok(Value::Number(n)),
54                    _ => return Err(FromSqlError::InvalidType), // FIXME
55                }
56            }
57            ValueRef::Null => Ok(Value::Null),
58        }
59        .map_err(|err| FromSqlError::Other(Box::new(err)))
60    }
61}
62
63#[cfg(test)]
64mod test {
65    use crate::types::ToSql;
66    use crate::{Connection, Result};
67    use serde_json::{Number, Value};
68
69    fn checked_memory_handle() -> Result<Connection> {
70        let db = Connection::open_in_memory()?;
71        db.execute_batch("CREATE TABLE foo (t TEXT, b BLOB)")?;
72        Ok(db)
73    }
74
75    #[test]
76    fn test_json_value() -> Result<()> {
77        let db = checked_memory_handle()?;
78
79        let json = r#"{"foo": 13, "bar": "baz"}"#;
80        let data: Value = serde_json::from_str(json).unwrap();
81        db.execute(
82            "INSERT INTO foo (t, b) VALUES (?1, ?2)",
83            [&data as &dyn ToSql, &json.as_bytes()],
84        )?;
85
86        let t: Value = db.one_column("SELECT t FROM foo")?;
87        assert_eq!(data, t);
88        let b: Value = db.one_column("SELECT b FROM foo")?;
89        assert_eq!(data, b);
90        Ok(())
91    }
92
93    #[test]
94    fn test_to_sql() -> Result<()> {
95        let db = Connection::open_in_memory()?;
96
97        let v: Option<String> = db.query_row("SELECT ?", [Value::Null], |r| r.get(0))?;
98        assert_eq!(None, v);
99        let v: String = db.query_row("SELECT ?", [Value::Bool(true)], |r| r.get(0))?;
100        assert_eq!("true", v);
101        let v: i64 = db.query_row("SELECT ?", [Value::Number(Number::from(1))], |r| r.get(0))?;
102        assert_eq!(1, v);
103        let v: f64 = db.query_row(
104            "SELECT ?",
105            [Value::Number(Number::from_f64(0.1).unwrap())],
106            |r| r.get(0),
107        )?;
108        assert_eq!(0.1, v);
109        let v: String =
110            db.query_row("SELECT ?", [Value::String("text".to_owned())], |r| r.get(0))?;
111        assert_eq!("\"text\"", v);
112        Ok(())
113    }
114
115    #[test]
116    fn test_from_sql() -> Result<()> {
117        let db = Connection::open_in_memory()?;
118
119        let v: Value = db.one_column("SELECT NULL")?;
120        assert_eq!(Value::Null, v);
121        let v: Value = db.one_column("SELECT 'null'")?;
122        assert_eq!(Value::Null, v);
123        let v: Value = db.one_column("SELECT 'true'")?;
124        assert_eq!(Value::Bool(true), v);
125        let v: Value = db.one_column("SELECT 1")?;
126        assert_eq!(Value::Number(Number::from(1)), v);
127        let v: Value = db.one_column("SELECT 0.1")?;
128        assert_eq!(Value::Number(Number::from_f64(0.1).unwrap()), v);
129        let v: Value = db.one_column("SELECT '\"text\"'")?;
130        assert_eq!(Value::String("text".to_owned()), v);
131        let v: Result<Value> = db.one_column("SELECT 'text'");
132        assert!(v.is_err());
133        Ok(())
134    }
135}
rusqlite/types/serde_json.rs

rusqlite/types/
serde_json.rs
