Struct Connection 

pub struct Connection { /* private fields */ }

An open connection to a SQLite database.

Examples

Load a set of rows from the default SQLite database, and iterate over them.

use spin_sdk::sqlite::{Connection, Value};

let db = Connection::open_default()?;

let query_result = db.execute(
    "SELECT * FROM users WHERE age >= ?",
    &[Value::Integer(min_age)]
)?;

let name_index = query_result.columns.iter().position(|c| c == "name").unwrap();

for row in &query_result.rows {
    let name: &str = row.get(name_index).unwrap();
    println!("Found user {name}");
}

Use the QueryResult::rows() wrapper to access a column by name. This is simpler and more readable but incurs a lookup on each access, so is not recommended when iterating a data set.

let db = Connection::open_default()?;
let query_result = db.execute(
    "SELECT * FROM users WHERE id = ?",
    &[Value::Integer(user_id)]
)?;
let name = query_result.rows().next().and_then(|r| r.get::<&str>("name")).unwrap();

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

use spin_sdk::sqlite::Connection;

let db = Connection::open("customer-data")?;
let query_result = db.execute("SELECT COUNT(*) FROM users", &[])?;
let count = query_result.rows.first().and_then(|r| r.get::<usize>(0)).unwrap();

Delete rows from a SQLite database. The usual Connection::execute() syntax is used but the query result is always empty.

use spin_sdk::sqlite::{Connection, Value};

let db = Connection::open("customer-data")?;
db.execute("DELETE FROM users WHERE age < ?", &[Value::Integer(min_age)])?;

A handle to an open sqlite instance

Implementations

impl Connection

pub fn open_default() -> Result<Self, Error>

Open a connection to the default database

impl Connection

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

Open a connection to a named database instance.

If database is “default”, the default instance is opened.

error::no-such-database will be raised if the name is not recognized.

impl Connection

pub fn execute( &self, statement: &str, parameters: &[Value], ) -> Result<QueryResult, Error>

Execute a statement returning back data if there is any

Trait Implementations

impl Debug for Connection

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

Formats the value using the given formatter.