use polars::sql::SQLContext;

fn main() {
    let mut ctx = SQLContext::new();

    let query = r#"
WITH a AS (
    SELECT 0 AS k
), b AS (
    SELECT 0 AS k
), c AS (
    SELECT 0 AS k
)
SELECT k FROM a JOIN c on a.k = c.k
UNION ALL
SELECT k FROM b JOIN c on b.k = c.k
"#;

    println!("Executing SQL query:");
    println!("{query}");
    println!();

    match ctx.execute(query) {
        Ok(lf) => {
            println!("Query executed successfully!");
            let result = lf.collect().unwrap();
            println!("Result:\n{result}");
        }
        Err(e) => {
            println!("ERROR: {e}");
        }
    }
}