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up vote 3 down vote favorite

I am trying to get my JSON encoded array formatted properly. Here is my PHP MySQL Query:

$query = "SELECT date, value1, value2
            FROM testdata
            ORDER BY date ASC";  


         $result = mysql_query($query);
         $myChartData = array();
          while($row = mysql_fetch_assoc($result)){
            $myChartData[] = $row;
                        }

   <script type="text/javascript">
    var chartData = <?php echo json_encode($myChartData); ?>;

From the console, the object looks like this:

[Object { date="2011-02-23", value1="133034", value2="12105.78"},
 Object { date="2011-02-24", value1="122290", value2="12068.50"},
 Object { date="2011-03-08", value1="453142", value2="12214.38"}]

The quotation marks around the date stays, but the ones on value1 and value2 need to be stripped out.

Self-teaching noob at all of this...Thanks for your help!

share|improve this question
 
What have you tried? You can use regex or split on the string –  Hitham S. AlQadheeb May 2 '12 at 20:45
 
You should convert those strings value1 and value2 to numbers before you JSON encode. –  Dan D. May 2 '12 at 20:46
 
You should consider JSON as a data format. It's a native JavaScript object so it's fast and you don't need the same amount of parsing to get to your data. secretgeek.net/json_3mins.asp –  Diodeus May 2 '12 at 20:47
 
@ControlAltDel not true. "A value can be a string in double quotes, or a number, or true or false or null, or an object or an array" json.org –  paislee May 2 '12 at 20:47
1  
@Diodeus: That's what he is doing. json_encode($myChartData) creates JSON. And JSON is not JavaScript. It is format that was inspired by JavaScript's object literal syntax. That's all. –  Felix Kling May 2 '12 at 20:48
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2 Answers

up vote 1 down vote accepted

A simple javascript solution:

function formatChartData(data) {
    for(var i = 0, length = data.length; i < length; i++) {
        data[i].value1 = parseInt(data[i].value1, 10);
        data[i].value2 = parseFloat(data[i].value2);
    }
    return data;
}

var chartData = formatChartData(<?php echo json_encode($myChartData); ?>);
share|improve this answer
 
Joe, so far this did what I asked to do! I have to plug it in to the whole script to see if it produces the charts, but the output looks like this: [Object { date="2011-02-23", value1=133034, value2=12105.78}, Object { date="2011-02-24", value1=122290, value2=12068.5}, Object { date="2011-03-08", value1=453142, value2=12214.38}] Which leaves me wondering if it's a fix for something I did wrong in the first place, or what... I'll work on it, thanks! –  EotS May 3 '12 at 3:10
 
Well, it definitely works! Thanks Joe! Although, I think it's fixing a mistake I've made in the first place... –  EotS May 3 '12 at 14:55
add comment
up vote 2 down vote

First:

The quotation marks around the date stays, but the ones on value1 and value2 need to be stripped out.

There are no quotation marks! What you see as a visual representation of the data contained in chartData. In this case it is an array with three objects, each having three properties containing strings.
What you want is to convert some of these strings into numbers (integers, floating point).

The correct way

It seems you are not storing the data correctly in your DB. If the values were numbers, they would be encoded as such.

The only reasonable solution is to fix it at that end. That means you have to define the data types of your DB fields properly.

The workaround

If, for some reason, you cannot fix the DB (you should try really hard), you have the possibility to convert the strings to numbers

If you are new to JavaScript, you might want to read Working with Objects [MDN] first.

share|improve this answer
 
Thanks for the feedback Felix. I'm much better with RDB than I am javascript, and I even went back and double-checked to make sure I didn't do anything stoopid when I created the DB. In the MySQL DB, date is stored as a 'date", value1 is stored as int(11) and value2 is stored as decimal (8,2). Which brings up one of the puzzles I've found in researching my problem. The dataset is being sent to Amcharts, and the other guys had problems with the column names in quotes. I was a bit miffed as to why I had the opposite issue... –  EotS May 3 '12 at 2:41
 
I was wondering if what I was viewing in the console was the actual data being passed to Amcharts. Still trying to get my head around this... –  EotS May 3 '12 at 2:55
 
Mmmh. That's interesting. Maybe my PHP/DB is a bit rusty, but if the data type in the DB is correct, you should get the correct data type in PHP. What is an example for the output var_dump($row) in your loop? –  Felix Kling May 3 '12 at 8:02
 
Rats. The output looks like: array(3) { ["date"]=> string(10) "2011-02-23" ["value1"]=> string(6) "133034" ["value2"]=> string(8) "12105.78" } array(3) { ["date"]=> string(10) "2011-02-24" ["value1"]=> string(6) "122290" ["value2"]=> string(8) "12068.50" } array(3) { ["date"]=> string(10) "2011-03-08" ["value1"]=> string(6) "453142" ["value2"]=> string(8) "12214.38" } –  EotS May 3 '12 at 14:55
 
So it looks like it's getting value1 and value2 as strings (?) –  EotS May 3 '12 at 14:56
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