Connection

Struct Connection 

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pub struct Connection { /* private fields */ }
Expand description

An open connection to a MySQL database.

§Examples

Load a set of rows from a local PostgreSQL database, and iterate over them.

use spin_sdk::mysql::{Connection, Decode, ParameterValue};

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}");
}

Perform an aggregate (scalar) operation over a table. The result set contains a single column, with a single row.

use spin_sdk::mysql::{Connection, Decode};

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])?;

Delete rows from a MySQL table. This uses Connection::execute() instead of the query method.

use spin_sdk::mysql::{Connection, ParameterValue};

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())]
)?;

A connection to a MySQL database.

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impl Connection

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pub fn open(address: &str) -> Result<Connection, Error>

Open a connection to the MySQL instance at address.

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impl Connection

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pub fn query( &self, statement: &str, params: &[ParameterValue], ) -> Result<RowSet, Error>

query the database: select

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impl Connection

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pub fn execute( &self, statement: &str, params: &[ParameterValue], ) -> Result<(), Error>

execute command to the database: insert, update, delete

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impl Debug for Connection

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fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter. Read more

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impl<T> Any for T
where T: 'static + ?Sized,

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fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more
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impl<T> Borrow<T> for T
where T: ?Sized,

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fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more
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impl<T> BorrowMut<T> for T
where T: ?Sized,

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fn borrow_mut(&mut self) -> &mut T

Mutably borrows from an owned value. Read more
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impl<T> From<T> for T

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fn from(t: T) -> T

Returns the argument unchanged.

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impl<T, U> Into<U> for T
where U: From<T>,

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fn into(self) -> U

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

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impl<T> Same for T

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type Output = T

Should always be Self
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impl<T, U> TryFrom<U> for T
where U: Into<T>,

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type Error = Infallible

The type returned in the event of a conversion error.
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fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

Performs the conversion.
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impl<T, U> TryInto<U> for T
where U: TryFrom<T>,

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type Error = <U as TryFrom<T>>::Error

The type returned in the event of a conversion error.
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fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

Performs the conversion.
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impl<V, T> VZip<V> for T
where V: MultiLane<T>,

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fn vzip(self) -> V