registerUser(params, callback) {
    var sql = "INSERT INTO users_data (first_name, last_name, email, role, registration_date, active, password) VALUES ('"+params.fName+"', '"+params.lName+"', '"+params.email+"', '"+params.role+"', '"+params.date+"', '"+1+"', '"+params.hashedPass+"')";
    con.query(sql, function (err, result) {
        if (err) throw err;
        callback(result);
    });
}

bcrypt.genSalt(saltRounds, function(err, salt){
        bcrypt.hash(query.password, salt, function(err, hashedPass){
            console.log(hashedPass); //I get the hash printed here with no problems
            write.registerUser({
                data,
                fName,
                lName,
                email,
                role,
                date,
                hashedPass
            }, function(results){
                console.log(results)
                return();
            });
        });
    });