spin-sdk 6.0.0

//! MySQL relational database storage.
//!
//! You can use the [`Decode`] trait to convert a [`DbValue`] to a
//! suitable Rust type. The following table shows available conversions.
//!
//! # Types
//!
//! | Rust type | WIT (db-value)      | MySQL type(s)           |
//! |-----------|---------------------|-------------------------|
//! | `bool`    | int8(s8)            | TINYINT(1), BOOLEAN     |
//! | `i8`      | int8(s8)            | TINYINT                 |
//! | `i16`     | int16(s16)          | SMALLINT                |
//! | `i32`     | int32(s32)          | MEDIUM, INT             |
//! | `i64`     | int64(s64)          | BIGINT                  |
//! | `u8`      | uint8(u8)           | TINYINT UNSIGNED        |
//! | `u16`     | uint16(u16)         | SMALLINT UNSIGNED       |
//! | `u32`     | uint32(u32)         | INT UNSIGNED            |
//! | `u64`     | uint64(u64)         | BIGINT UNSIGNED         |
//! | `f32`     | floating32(float32) | FLOAT                   |
//! | `f64`     | floating64(float64) | DOUBLE                  |
//! | `String`  | str(string)         | VARCHAR, CHAR, TEXT     |
//! | `Vec<u8>` | binary(list\<u8\>)  | VARBINARY, BINARY, BLOB |

#[doc(hidden)]
/// Module containing wit bindgen generated code.
///
/// This is only meant for internal consumption.
pub mod wit {
    #![allow(missing_docs)]
    use crate::wit_bindgen;

    wit_bindgen::generate!({
        runtime_path: "crate::wit_bindgen::rt",
        world: "spin-sdk-mysql",
        path: "wit",
        generate_all,
    });
}

/// An open connection to a MySQL database.
///
/// # Examples
///
/// Load a set of rows from a local MySQL database, and iterate over them.
///
/// ```no_run
/// use spin_sdk::mysql::{Connection, Decode, ParameterValue};
///
/// # fn run() -> anyhow::Result<()> {
/// # let min_age = 0;
/// let db = Connection::open("mysql://root:my_password@localhost/mydb")?;
///
/// let query_result = db.query(
///     "SELECT * FROM users WHERE age < ?",
///     &[ParameterValue::Int32(20)]
/// )?;
///
/// let name_index = query_result.columns.iter().position(|c| c.name == "name").unwrap();
///
/// for row in &query_result.rows {
///     let name = String::decode(&row[name_index])?;
///     println!("Found user {name}");
/// }
/// # Ok(())
/// # }
/// ```
///
/// Perform an aggregate (scalar) operation over a table. The result set
/// contains a single column, with a single row.
///
/// ```no_run
/// use spin_sdk::mysql::{Connection, Decode};
///
/// # fn run() -> anyhow::Result<()> {
/// let db = Connection::open("mysql://root:my_password@localhost/mydb")?;
///
/// let query_result = db.query("SELECT COUNT(*) FROM users", &[])?;
///
/// assert_eq!(1, query_result.columns.len());
/// assert_eq!("COUNT(*)", query_result.columns[0].name);
/// assert_eq!(1, query_result.rows.len());
///
/// let count = i64::decode(&query_result.rows[0][0])?;
/// # Ok(())
/// # }
/// ```
///
/// Delete rows from a MySQL table. This uses [Connection::execute()]
/// instead of the `query` method.
///
/// ```no_run
/// use spin_sdk::mysql::{Connection, ParameterValue};
///
/// # fn run() -> anyhow::Result<()> {
/// let db = Connection::open("mysql://root:my_password@localhost/mydb")?;
///
/// let rows_affected = db.execute(
///     "DELETE FROM users WHERE name = ?",
///     &[ParameterValue::Str("Baldrick".to_owned())]
/// )?;
/// # Ok(())
/// # }
/// ```
#[doc(inline)]
pub use wit::fermyon::spin::mysql::Connection;

/// The result of a database query.
///
/// # Examples
///
/// Load a set of rows from a local MySQL database, and iterate over them
/// selecting one field from each. The columns collection allows you to find
/// column indexes for column names; you can bypass this lookup if you name
/// specific columns in the query.
///
/// ```no_run
/// use spin_sdk::mysql::{Connection, Decode, ParameterValue};
///
/// # fn run() -> anyhow::Result<()> {
/// # let min_age = 0;
/// let db = Connection::open("mysql://root:my_password@localhost/mydb")?;
///
/// let query_result = db.query(
///     "SELECT * FROM users WHERE age >= ?",
///     &[ParameterValue::Int32(min_age)]
/// )?;
///
/// let name_index = query_result.columns.iter().position(|c| c.name == "name").unwrap();
///
/// for row in &query_result.rows {
///     let name = String::decode(&row[name_index])?;
///     println!("Found user {name}");
/// }
/// # Ok(())
/// # }
/// ```
#[doc(inline)]
pub use wit::fermyon::spin::mysql::RowSet;

#[doc(inline)]
pub use wit::fermyon::spin::mysql::Error as MysqlError;

#[doc(inline)]
pub use wit::fermyon::spin::rdbms_types::*;

/// A MySQL error
#[derive(Debug, thiserror::Error)]
pub enum Error {
    /// Failed to deserialize [`DbValue`]
    #[error("error value decoding: {0}")]
    Decode(String),
    /// MySQL query failed with an error
    #[error(transparent)]
    MysqlError(#[from] MysqlError),
}

/// A type that can be decoded from the database.
pub trait Decode: Sized {
    /// Decode a new value of this type using a [`DbValue`].
    fn decode(value: &DbValue) -> Result<Self, Error>;
}

impl<T> Decode for Option<T>
where
    T: Decode,
{
    fn decode(value: &DbValue) -> Result<Self, Error> {
        match value {
            DbValue::DbNull => Ok(None),
            v => Ok(Some(T::decode(v)?)),
        }
    }
}

impl Decode for bool {
    fn decode(value: &DbValue) -> Result<Self, Error> {
        match value {
            DbValue::Int8(0) => Ok(false),
            DbValue::Int8(1) => Ok(true),
            _ => Err(Error::Decode(format_decode_err(
                "TINYINT(1), BOOLEAN",
                value,
            ))),
        }
    }
}

impl Decode for i8 {
    fn decode(value: &DbValue) -> Result<Self, Error> {
        match value {
            DbValue::Int8(n) => Ok(*n),
            _ => Err(Error::Decode(format_decode_err("TINYINT", value))),
        }
    }
}

impl Decode for i16 {
    fn decode(value: &DbValue) -> Result<Self, Error> {
        match value {
            DbValue::Int16(n) => Ok(*n),
            _ => Err(Error::Decode(format_decode_err("SMALLINT", value))),
        }
    }
}

impl Decode for i32 {
    fn decode(value: &DbValue) -> Result<Self, Error> {
        match value {
            DbValue::Int32(n) => Ok(*n),
            _ => Err(Error::Decode(format_decode_err("INT", value))),
        }
    }
}

impl Decode for i64 {
    fn decode(value: &DbValue) -> Result<Self, Error> {
        match value {
            DbValue::Int64(n) => Ok(*n),
            _ => Err(Error::Decode(format_decode_err("BIGINT", value))),
        }
    }
}

impl Decode for u8 {
    fn decode(value: &DbValue) -> Result<Self, Error> {
        match value {
            DbValue::Uint8(n) => Ok(*n),
            _ => Err(Error::Decode(format_decode_err("UNSIGNED TINYINT", value))),
        }
    }
}

impl Decode for u16 {
    fn decode(value: &DbValue) -> Result<Self, Error> {
        match value {
            DbValue::Uint16(n) => Ok(*n),
            _ => Err(Error::Decode(format_decode_err("UNSIGNED SMALLINT", value))),
        }
    }
}

impl Decode for u32 {
    fn decode(value: &DbValue) -> Result<Self, Error> {
        match value {
            DbValue::Uint32(n) => Ok(*n),
            _ => Err(Error::Decode(format_decode_err(
                "UNISIGNED MEDIUMINT, UNSIGNED INT",
                value,
            ))),
        }
    }
}

impl Decode for u64 {
    fn decode(value: &DbValue) -> Result<Self, Error> {
        match value {
            DbValue::Uint64(n) => Ok(*n),
            _ => Err(Error::Decode(format_decode_err("UNSIGNED BIGINT", value))),
        }
    }
}

impl Decode for f32 {
    fn decode(value: &DbValue) -> Result<Self, Error> {
        match value {
            DbValue::Floating32(n) => Ok(*n),
            _ => Err(Error::Decode(format_decode_err("FLOAT", value))),
        }
    }
}

impl Decode for f64 {
    fn decode(value: &DbValue) -> Result<Self, Error> {
        match value {
            DbValue::Floating64(n) => Ok(*n),
            _ => Err(Error::Decode(format_decode_err("DOUBLE", value))),
        }
    }
}

impl Decode for Vec<u8> {
    fn decode(value: &DbValue) -> Result<Self, Error> {
        match value {
            DbValue::Binary(n) => Ok(n.to_owned()),
            _ => Err(Error::Decode(format_decode_err("BINARY, VARBINARY", value))),
        }
    }
}

impl Decode for String {
    fn decode(value: &DbValue) -> Result<Self, Error> {
        match value {
            DbValue::Str(s) => Ok(s.to_owned()),
            _ => Err(Error::Decode(format_decode_err(
                "CHAR, VARCHAR, TEXT",
                value,
            ))),
        }
    }
}

fn format_decode_err(types: &str, value: &DbValue) -> String {
    format!("Expected {} from the DB but got {:?}", types, value)
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn boolean() {
        assert!(bool::decode(&DbValue::Int8(1)).unwrap());
        assert!(bool::decode(&DbValue::Int8(3)).is_err());
        assert!(bool::decode(&DbValue::Int32(0)).is_err());
        assert!(Option::<bool>::decode(&DbValue::DbNull).unwrap().is_none());
    }

    #[test]
    fn int8() {
        assert_eq!(i8::decode(&DbValue::Int8(0)).unwrap(), 0);
        assert!(i8::decode(&DbValue::Int32(0)).is_err());
        assert!(Option::<i8>::decode(&DbValue::DbNull).unwrap().is_none());
    }

    #[test]
    fn int16() {
        assert_eq!(i16::decode(&DbValue::Int16(0)).unwrap(), 0);
        assert!(i16::decode(&DbValue::Int32(0)).is_err());
        assert!(Option::<i16>::decode(&DbValue::DbNull).unwrap().is_none());
    }

    #[test]
    fn int32() {
        assert_eq!(i32::decode(&DbValue::Int32(0)).unwrap(), 0);
        assert!(i32::decode(&DbValue::Boolean(false)).is_err());
        assert!(Option::<i32>::decode(&DbValue::DbNull).unwrap().is_none());
    }

    #[test]
    fn int64() {
        assert_eq!(i64::decode(&DbValue::Int64(0)).unwrap(), 0);
        assert!(i64::decode(&DbValue::Boolean(false)).is_err());
        assert!(Option::<i64>::decode(&DbValue::DbNull).unwrap().is_none());
    }

    #[test]
    fn uint8() {
        assert_eq!(u8::decode(&DbValue::Uint8(0)).unwrap(), 0);
        assert!(u8::decode(&DbValue::Uint32(0)).is_err());
        assert!(Option::<u16>::decode(&DbValue::DbNull).unwrap().is_none());
    }

    #[test]
    fn uint16() {
        assert_eq!(u16::decode(&DbValue::Uint16(0)).unwrap(), 0);
        assert!(u16::decode(&DbValue::Uint32(0)).is_err());
        assert!(Option::<u16>::decode(&DbValue::DbNull).unwrap().is_none());
    }

    #[test]
    fn uint32() {
        assert_eq!(u32::decode(&DbValue::Uint32(0)).unwrap(), 0);
        assert!(u32::decode(&DbValue::Boolean(false)).is_err());
        assert!(Option::<u32>::decode(&DbValue::DbNull).unwrap().is_none());
    }

    #[test]
    fn uint64() {
        assert_eq!(u64::decode(&DbValue::Uint64(0)).unwrap(), 0);
        assert!(u64::decode(&DbValue::Boolean(false)).is_err());
        assert!(Option::<u64>::decode(&DbValue::DbNull).unwrap().is_none());
    }

    #[test]
    fn floating32() {
        assert!(f32::decode(&DbValue::Floating32(0.0)).is_ok());
        assert!(f32::decode(&DbValue::Boolean(false)).is_err());
        assert!(Option::<f32>::decode(&DbValue::DbNull).unwrap().is_none());
    }

    #[test]
    fn floating64() {
        assert!(f64::decode(&DbValue::Floating64(0.0)).is_ok());
        assert!(f64::decode(&DbValue::Boolean(false)).is_err());
        assert!(Option::<f64>::decode(&DbValue::DbNull).unwrap().is_none());
    }

    #[test]
    fn str() {
        assert_eq!(
            String::decode(&DbValue::Str(String::from("foo"))).unwrap(),
            String::from("foo")
        );

        assert!(String::decode(&DbValue::Int32(0)).is_err());
        assert!(Option::<String>::decode(&DbValue::DbNull)
            .unwrap()
            .is_none());
    }
}