All series on a given axis must be of the same data type

Question

I early had problems with formatting the time, but now having problem with showing the google chart visualiszation out of this error: All series on a given axis must be of the same data type.

This is the goal, with date and time: http://jsbin.com/yaqew/1/edit

As I have been notified the google chart constructor will not accept the time/date string: https://developers.google.com/chart/interactive/docs/reference#dataparam

Database:

PHP:

<?php

    $con=mysql_connect("localhost","root","") or die("Failed to connect with database!!!!");
    mysql_select_db("chart", $con);

    $sth = mysql_query("SELECT * FROM googlechart");

    $rows = array();
    //flag is not needed
    $flag = true;
    $table = array();

    $table['cols'] = array(

    array('label' => 'Time', 'type' => 'datetime'),
    array('label' => 'Date', 'type' => 'datetime'),
    array('label' => 'PH',      'type' => 'number'),
    array('label' => 'temperature','type' => 'number'), 
    array('label' => 'Chlorine','type' => 'number'),
    );

    $rows = array();

    while($r = mysql_fetch_assoc($sth)) {

    // assumes dates are in the format "yyyy-MM-dd"
    $dateString = $r['Date'];
    $dateArray = explode('-', $dateString);
    $year = $dateArray[0];
    $month = $dateArray[1] - 1; // subtract 1 to convert to javascript's 0-indexed months
    $day = $dateArray[2];

    echo $dateString."<br>";

    // assumes time is in the format "hh:mm:ss"
    $timeString = $r['Time'];
    $timeArray = explode(':', $timeString);
    $hours = $timeArray[0];
    $minutes = $timeArray[1];
    $seconds = $timeArray[2];

    echo $timeString;

    $temp = array();
    $temp[] = array('v' => "Date($year, $month, $day, $hours, $minutes, $seconds)"); 
    $temp[] = array('v' => (string) $r['PH']);
    $temp[] = array('v' => (string) $r['temperature']);
    $temp[] = array('v' => (string) $r['Chlorine']);

    $rows[] = array('c' => $temp);

    }

    $table['rows'] = $rows;
    $jsonTable = json_encode($table);
    /* echo $jsonTable; */  

?>

Html/Javascript:

<script type="text/javascript" src="https://www.google.com/jsapi"></script>
    <script type="text/javascript">
      google.load("visualization", "1", {packages:["corechart"]});
      google.setOnLoadCallback(drawChart);

      function drawChart() {
        var data = new google.visualization.DataTable(<?=$jsonTable?>);



        var options = {
        /*width: 900, height: 900, */
          title: 'Visualization',
          curveType: 'function', 
           legend: { position: 'bottom' },
           pointSize: 12,
        vAxis: {title: "Values", titleTextStyle: {italic: false}},
        hAxis: {title: "Time", titleTextStyle: {italic: false}},
        explorer: { 
                actions: ['dragToZoom', 'rightClickToReset'], 
                axis: 'vertical'
            }


        };

        var chart = new google.visualization.LineChart(document.getElementById('chart_div'));
        chart.draw(data, options);


      }

Answer 1

Your column definitions are not correct: you want only 1 column for date & time, not two:

$table['cols'] = array(
    array('label' => 'Date & Time', 'type' => 'datetime'),
    array('label' => 'PH', 'type' => 'number'),
    array('label' => 'temperature','type' => 'number'), 
    array('label' => 'Chlorine','type' => 'number')
);