How can I write a php app to access a mysql database and pass the data back to my javascript app.?

Answer 1

Remember:
PhP runs on your SERVER, so does MySQL.
Javascript runs on the CLIENT.
So, PhP runs FIRST:
1. 2. get the $parameter data from MySQL
3. echo ("");
6. ?>
This runs on the server.
line 1: tells the server to run PhP
line 2: you interrogate MySQL and return "$parameter"
(say you get "1234")
line 3: PhP sends to client:

On the client, when you get "view source", you get: