How do I get a value instead of Err in Rust?

Question

I'm querying a database and putting the results into a struct.

    let mut stmt = conn.prepare("SELECT operator, site, starttime, endtime......");
    let rows = stmt.query_map([], |row| {
        Ok(ti_data {
            operator: row.get(0)?,
            site: row.get(1)?,
            starttime: row.get(2)?,
            endtime: row.get(3)?,
            //more data here
          })
    };

Some values will be null and I can't change that since the data is created elsewhere and the code will panic if I try to use elements with null values. How can I replace null with 0 or ""?

I'm new to Rust and used to be checking values myself in C/C++/C#.

I would like to have something like

    if (row.get(i).? == None) {
        return 0;
    }