SQLite in memory example

---

• sqlite

• In this example we use an in-memory database.
• That's useful for the examples and it can be also useful if we have a lot of data on the disk that we would like analyze using SQL statements but we don't need to store the data in a database.

• In general it is not a good idea to have values in the SQL statements, especially not variables, but in this first exampleswe use that for simplicity.

examples/sqlite/in-memory-example/Cargo.toml

[package]
name = "in-memory-example"
version = "0.1.0"
edition = "2021"

# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html

[dependencies]
sqlite = "0.32.0"

examples/sqlite/in-memory-example/src/main.rs

use sqlite::State;

fn main() {
    let connection = sqlite::open(":memory:").unwrap();
    connection.execute("CREATE TABLE users (name TEXT, age INTEGER);").unwrap();
    connection.execute("INSERT INTO users VALUES ('Alice', 42);").unwrap();
    connection.execute("INSERT INTO users VALUES ('Bob', 69);").unwrap();

    let query = "SELECT * FROM users";
    //let query = "SELECT * FROM users WHERE age > 50";
    let mut statement = connection.prepare(query).unwrap();

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

}

name = Alice
age = 42
name = Bob
age = 69