serde_db/de/
db_value_into.rs

1use crate::de::conversion_error::ConversionError;
2
3/// Converts the given database value into a specific rust type.
4///
5/// We recommend to implement `try_into` as gracefully as possible, i.e.,
6/// supporting as many conversions as possible. For the numeric
7/// types this requires some lines of code, but the effort pays off for the users.
8///
9/// Example:
10///
11/// ```rust,ignore
12/// impl DbValueInto<u32> for MyDbValue {
13///     fn try_into(self) -> Result<u32, ConversionError> {
14///         match self {
15///             MyDbValue::TINYINT(u) => Ok(u as u32),
16///
17///             MyDbValue::SMALLINT(i) => if i >= 0 {
18///                 Ok(i as u32)
19///             } else {
20///                 Err(ConversionError::NumberRange(...))
21///             }
22///
23///             MyDbValue::INT(i) => if i >= 0 {
24///                 Ok(i as u32)
25///             } else {
26///                 Err(ConversionError::NumberRange(...))
27///             }
28///
29///             MyDbValue::BIGINT(i) => if (i >= 0) && (i <= u32::MAX as i64) {
30///                 Ok(i as u32)
31///             } else {
32///                 Err(ConversionError::NumberRange(...))
33///             }
34///
35///             _ => Err(ConversionError::ValueType(...)),
36///         }
37///     }
38///  }
39/// ```
40pub trait DbValueInto<T> {
41    /// Converts the database value into the target rust type.
42    ///
43    /// # Errors
44    ///
45    /// `ConversionError` if the value cannot be converted into the target type.
46    fn try_into(self) -> Result<T, ConversionError>;
47}
serde_db/de/db_value_into.rs

serde_db/de/
db_value_into.rs
