Ajax / JSON / PHP database data - php

Question

I'm more of a designer but I need to grab some data from a database. I would be able to get what I need without problem using PHP but I'm creating a mobile app in Phonegap so can't use anything other than HTML, CSS or JS.
I've read that this can be done in a PHP file on the server, encoded to JSON and then grabbed in the HTML with Ajax.
Can anyone show me how do I do this, as simply as possible please?

Answer 1

Javascript file
$.ajax({
type: "GET",
dataType: "JSON",
url: "php/phpDb.model.php",
data: {
sataVariable: "here is some data send with GET method"
},
success: function(data) {
console.log(data);
},
error: function(data) {
console.log(data);
}
});
php file (phpDb.model.php)
// Connect to database
$con = mysqli_connect("host", "userName", "password", "database")
or die('{ "error" : true, "errorMessage" : "Cannot connect to database '.mysqli_error($con).'"}');
// Query
$sqlCalling = "SELECT * FROM table WHERE ";
$result = mysqli_query($con,$sqlCalling);
$rowCalling = mysqli_fetch_array($resultCalling);
mysqli_close($con);
//getting column_1 and column_2
$column_1 = $rowCalling['column_1'];
$column_2 = $rowCalling['column_2'];
// Return a JSON parseable array
return array(
"column_1" => $column_1 ,
"column_2" => $column_2 ,
);
This solution is very generic, you will most likely just replace the name of the tables and the name of column with what they actually are in your database.

Answer 2

This is a very basic example using jQuery:
//hello_world.js
$.ajax({
url:'hello_world.php',
type: 'POST'
data: { 'var' : 'Hello World' }
}).done(function(response){
alert(response); //Well now alert an json string based on your query..
});
//hello_world.php
$STH = $DBH->prepare("SELECT blabla FROM table WHERE column = ?");
$STH->execute(array($_POST['var']));
$STH->setFetchMode(PDO::FETCH_ASSOC);
$resultQuery = $STH->fetchAll();
echo json_encode($resultQuery); //