Parsing MySQL output to JSON extracting field names - php

Question

I'm getting some trouble with parsing the output of MySQL query in order to feed Highcharts. The biggest problem is that I would hawe 100+ data series, and I would like to don't refer to each column name in the parsing process, now the desired output would be something like that:
[
{'name':'TS','data':[4349,4375]}
{'name':'time1','data':[503,573]}
{'name':'time2','data':[500,506]}
{'name':'time3','data':[508,649]}
]
But I'm stuck with this output, where all the data are printed in the only first array:
[
{'name':'TS','data':[4349,503,573,500,4375,506,508,649,]}
{'name':'time1','data':[]}
{'name':'time2','data':[]}
{'name':'time3','data':[]}
]
The PHP code that I'm using is the following:
<?php
try {
$con= new PDO('mysql:host=localhost;dbname=test', "root", "");
$con->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
$query = "SELECT TIME_TO_SEC(TS) as TS, TIME_TO_SEC(time1) as time1, TIME_TO_SEC(time2) as time2, TIME_TO_SEC(time3) as time3 FROM time ORDER BY TS";
//first pass just gets the column names
print "[";
$result = $con->query($query);
//return only the first row (we only need field names)
$row = $result->fetch(PDO::FETCH_ASSOC);
//second query gets the data
$data = $con->query($query);
$data->setFetchMode(PDO::FETCH_ASSOC);
foreach ($row as $field => $value){
print "{'name':'$field','data':[";
foreach($data as $row){
foreach ($row as $name=>$value){
print " $value,";
}
}
print "]}";
}
print "]";
}
catch(PDOException $e) {
echo 'ERROR: ' . $e->getMessage();
}
?>
Any suggestion to how to solve that problem?

Answer 1

Looks like you're using $row multiple times causing the loops to create errors.
Rename your inner $row variable to something else, e.g. $innerData.
foreach ($row as $field => $value){
print "{'name':'$field','data':[";
foreach($data as $innerData){
foreach ($innerData as $name=>$innerValue){
print " $innerValue,";
}
}
print "]}";
}
But there seem to be more problems in your code.
You query the database with the $query, 2 times. You you would get 2 same result sets. Did you miss to insert the second query statement ?
Please include the results the queries will produce in mysql, without php. This way I can improve my answer or other may help you too.