JSFiddle - React, Tailwind, and code Playground

JavaScript

register(props, callback = null) {

    var sql = "INSERT INTO users (first_name,last_name,mob_no,user_name, password) VALUES (?,?,?,?,?)";
    var params = [props.first_name, props.last_name, props.mob_no, props.user_name, props.password];
    var query = db.query(sql, params, function(err, result) {

        // Check is callback is a function
        if (typeof callback === "function") {

            // If success
            if (err === null) {
                callback(0);
            }
            
            // On error return error
            else {
                callback(err);
            }
        }
        
        
    });
}