Example Project

Let's say we need to write a program to generate a report for the demo HR schema. This report shall list median salaries for each country of the specified region. The name of the region and the connection parameters shall be specified as environment variables (maybe because our program will be executed in a container).

Project Setup

cargo new median-salary

Then edit Cargo.toml and include Sibyl as a dependency:

[dependencies]
sibyl = { version="0.6", features=["blocking"] }

We will be writing a single threaded program, thus we will use Sibyl's blocking API.

Implement the Solution

fn main() -> sibyl::Result<()> {
    let oracle = sibyl::env()?;

    let dbname = std::env::var("DBNAME").expect("database name");
    let dbuser = std::env::var("DBUSER").expect("user name");
    let dbpass = std::env::var("DBPASS").expect("password");
    let region = std::env::var("REGION").expect("HR region");

    let session = oracle.connect(&dbname, &dbuser, &dbpass)?;

    let stmt = session.prepare("
        SELECT c.country_name, Median(e.salary)
          FROM hr.employees e
          JOIN hr.departments d ON d.department_id = e.department_id
          JOIN hr.locations l   ON l.location_id = d.location_id
          JOIN hr.countries c   ON c.country_id = l.country_id
          JOIN hr.regions r     ON r.region_id = c.region_id
         WHERE r.region_name = :REGION_NAME
      GROUP BY c.country_name
    ")?;

    let rows = stmt.query(&region)?;

    while let Some(row) = rows.next()? {
        let country_name : &str = row.get(0)?;
        let median_salary : u16 = row.get(1)?;
        println!("{:25}: {:>5}", country_name, median_salary);
    }
    Ok(())
}

Build and Run

cargo build

And then run it:

DBNAME=localhost/orcl DBUSER=sibyl DBPASS=Or4cl3 REGION=Americas cargo run

⚠ Note that depending on the Oracle client installed you might also need to adjust PATH on Windows or specify LD_LIBRARY_PATH on Linux:

LD_LIBRARY_PATH=/opt/instantclient_19_24 DBNAME=localhost/orcl DBUSER=sibyl DBPASS=Or4cl3 REGION=Americas cargo run

Expected Output

Canada                   :  9500
United States of America :  3250