Getting data from PHP to JSON - php

Question

So, I want to create dynamic donut chart, where the datas are from mySql database. But, the problem is in that chart, the datas get from JSON.
My question, how to use datas from PHP to be use for JSON datas. here're my progress so far :
<?php
$query_A = "SELECT COUNT(category) as catg FROM mydata ORDER BY category";
$result_A = mysql_query($query_A);
$query_B = "SELECT COUNT(category) as catg FROM mydata ORDER BY category";
$result_B = mysql_query($query_B);
//Print JSON
$prefix = '';
"[\n";
while ( $row_A = mysql_fetch_assoc( $result_A ) ) {
$prefix . " {<br>";
' "category": "' . "A" . '",' . "<br>";
' "value": ' . $row_A['catg'] . ',' . "<br>";
" }";
$prefix = ",\n";
}
while ( $row_B = mysql_fetch_assoc( $result_B ) ) {
$prefix . " {<br>";
' "category": "' . "B" . '",' . "<br>";
' "value": ' . $row_B['catg'] . ',' . "<br>";
" }";
$prefix = ",\n";
}
"\n]";
?>
And here're JSON datas from that donut chart :
<script type="text/javascript">
var chart = AmCharts.makeChart( "chartdiv", {
"type": "pie",
"theme": "light",
"dataProvider": [ {
"title": "New",
"value": 200
}, {
"title": "Returning",
"value": 9899
}, {
"title": "Back",
"value": 900
} ],
"titleField": "title",
"valueField": "value",
"labelRadius": 10,
"radius": "42%",
"innerRadius": "60%",
"labelText": "[[title]]",
"export": {
"enabled": true
}
} );
</script>
I want to use my mysql datas for that JSON datas. Thank you

Answer 1

There's a handy function called json_encode. Simply run your data through this function.
$json = json_encode($data); // returns a JSON string
By the way, have you tried googling for "PHP create JSON" or something similar? The time it took you to write this question, you would already have found a solution. Not to mention the time you wasted on trying to create the JSON yourself.
Just saying, you can save a lot of time by asking a search engine … you are usually not the first to have a particular problem.

Answer 2

I can't understand why there are two identical queries but that said.
<?php
$query_A = "SELECT COUNT(`category`) as 'catg' FROM `mydata` ORDER BY `category`";
$result_A = mysql_query( $query_A );
$query_B = "SELECT COUNT(`category`) as 'catg' FROM `mydata` ORDER BY `category`";
$result_B = mysql_query( $query_B );
if( $result_A ){
$data=array();
while ( $row_A = mysql_fetch_assoc( $result_A ) ) {
$data[]=array('category'=>'A', 'value'=>$row_A['catg'] );
}
$json_A=json_encode( $data );
}
if( $result_B ){
$data=array();
while ( $row_B = mysql_fetch_assoc( $result_B ) ) {
$data[]=array('category'=>'B', 'value'=>$row_B['catg'] );
}
$json_B=json_encode( $data );
}
?>
Then, in your javascript you could do this:-
var json_a=<?php echo $json_A;?>;
var json_b=<?php echo $json_B;?>;