How can I join multiple SQL tables using the IDs?
You want something more like this:
SELECT TableA.*, TableB.*, TableC.*, TableD.*FROM TableA JOIN TableB ON TableB.aID = TableA.aID JOIN TableC ON TableC.cID = TableB.cID JOIN TableD ON TableD.dID = TableA.dIDWHERE DATE(TableC.date)=date(now()) In your example, you are not actually including TableD. All you have to do is perform another join just like you have done before.
A note: you will notice that I removed many of your parentheses, as they really are not necessary in most of the cases you had them, and only add confusion when trying to read the code. Proper nesting is the best way to make your code readable and separated out.