JS: Promise resolution

I am new to javascript promises, I am using below code from NativeScript to query sqlite database and just want to return true if row exists and false otherwise:

function hasBookmark(url) {
    (new Sqlite("pakjobs.db")).then(db => {
        db.all("SELECT url FROM bookmarks WHERE url=?", [url]).then(rows => {
            return rows.length ? true : false;
        }, error => {
            console.log("hasBookmark ERROR", error);
            return false;
        });
    }, error => {
        console.log("hasBookmark ERROR", error);
        return false;
    });

    return false;
}

However function ALWAYS returns false.

Can anybody tell how do I return true if row exists and false otherwise ?

Thanks for the help