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Check If A sqlite Table Exists In Rust

This is what I'm using to see if a table exists in a sqlite database:

Code

use rusqlite::{Connection, Result};

fn table_exists(conn: Connection, table_name: &str) -> Result<bool> {
    let mut stmt = conn.prepare(
        "SELECT name FROM sqlite_master 
        WHERE type='table' AND name=?1",
    )?;
    let rows = stmt.query_map([table_name], |_| Ok(()))?;
    if rows.count() == 1 {
        Ok(true)
    } else {
        Ok(false)
    }
}

#[cfg(test)]
mod text {
    use super::*;
    use rusqlite::Connection;

    #[test]
    fn solo_table_does_not_exist() {
        let conn = Connection::open_in_memory().unwrap();
        let expected = false;
        let result = table_exists(conn, "alfa").unwrap();
        assert_eq!(expected, result);
    }

    #[test]
    fn solo_table_exists() {
        let conn = Connection::open_in_memory().unwrap();
        conn.execute("CREATE TABLE bravo (placeholder TEXT)", ())
            .unwrap();
        let expected = true;
        let result = table_exists(conn, "bravo").unwrap();
        assert_eq!(expected, result);
    }
}

Notes

  • This uses the rusqlte crate. There's one that's just called `sqlite`` but it has way less usage.

  • write up more details on how this works

References