Kontrak-SQLite

The package provides an interface to [Kontrak-SQLite][1].

The Example

Open a connection, create a table, and insert some rows:

let connection = kontrak_sqlite::open(":memory:").unwrap();

connection
    .execute(
        "
        CREATE TABLE users (name TEXT, age INTEGER);
        INSERT INTO users (name, age) VALUES ('Alice', 42);
        INSERT INTO users (name, age) VALUES ('Bob', 69);
        ",
    )
    .unwrap();

Select some rows and process them one by one as plain text:

connection
    .iterate("SELECT * FROM users WHERE age > 50", |pairs| {
        for &(column, value) in pairs.iter() {
            println!("{} = {}", column, value.unwrap());
        }
        true
    })
    .unwrap();

The same query using a prepared statement, which is much more efficient than the previous technique:

use kontrak_sqlite::State;

let mut statement = connection
    .prepare("SELECT * FROM users WHERE age > ?")
    .unwrap();

statement.bind(1, 50).unwrap();

while let State::Row = statement.next().unwrap() {
    println!("name = {}", statement.read::<String>(0).unwrap());
    println!("age = {}", statement.read::<i64>(1).unwrap());
}

The same query using a cursor, which is a wrapper around a prepared statement providing the concept of row and featuring all-at-once binding:

use kontrak_sqlite::Value;

let mut cursor = connection
    .prepare("SELECT * FROM users WHERE age > ?")
    .unwrap()
    .cursor();

cursor.bind(&[Value::Integer(50)]).unwrap();

while let Some(row) = cursor.next().unwrap() {
    println!("name = {}", row[0].as_string().unwrap());
    println!("age = {}", row[1].as_integer().unwrap());
}

Contribution

Your contribution is highly appreciated. Do not hesitate to open an issue or a pull request. Note that any contribution submitted for inclusion in the project will be licensed according to the terms given in LICENSE.md.