one to many PHP app - Query problems

[Adam Grey]

Hello! I hope I am in the right spot for some help with a PHP web app I am developing. It's basically a day planner. I am getting information from a PHP/HTML form.

So I have 2 tables a users (primary) and an events.

Users has fields: id( Auto increment/primary key/), username (unique/index), password (hashed), and email (index/unique)

(one to many relationship)

My events table has: id (primary key/index (Is this necessary?)), user_id (index/foreign key to users.id ), title(varchar), description(varchar), dateHappens(date) and createdOn(date)

So I hope I got the table set up right. I have the id of users to be primary and user_id of events to be foreign.

What is giving me problems:
So the dateHappens field is a date input by the user of an upcoming event.
createdOn is a field that stores the current date information

I am having trouble getting all of the events table information into the database. - The query is wrong.

Here is my current query, I hope this is sufficient information to get some help.

"INSERT INTO events(title, description, dateHappens, createdOn) VALUES(?,?,?,?)";

and I am trying to insert the data like this:

($user->getTitle(), $user->getDesc(), $user->getHappens(), NOW()));

Not sure how to get the foreign key of user_id from the primary key in the users table. In the sql query how do I get the referenced id primary key in the events table data?

Thanks for any help!