Hi Aliaksandr,

thanks for advice, you helped a lot.

Of course this skeleton requires some fine tuning, but it seems to be a good starting point.

Best regards,

István

Hi,

You can try the next approach:

1) Create a function which will generate new Chart after data changes:

   const createChart = ({ type, data, options }) => {
        return new Chart(ctx, { type, data, options });
   };

2) Save Chart parameters in variables, f.e. :

      let type = 'bar';
      let label = '# of Votes';
      let labels = ['Red', 'Blue', 'Yellow', 'Green', 'Purple', 'Orange'];
      let datasetData = [12, 19, 3, 5, 2, 3];
      let backgroundColor = [
        'rgba(255, 99, 132, 0.2)',
        'rgba(54, 162, 235, 0.2)',
        'rgba(255, 206, 86, 0.2)',
        'rgba(75, 192, 192, 0.2)',
        'rgba(153, 102, 255, 0.2)',
        'rgba(255, 159, 64, 0.2)'
      ];
      let borderColor = [
        'rgba(255,99,132,1)',
        'rgba(54, 162, 235, 1)',
        'rgba(255, 206, 86, 1)',
        'rgba(75, 192, 192, 1)',
        'rgba(153, 102, 255, 1)',
        'rgba(255, 159, 64, 1)'
      ];
      let borderWidth = 1;

      let datasets = [
        {
          label,
          data: datasetData,
          backgroundColor,
          borderColor,
          borderWidth
        }
      ];

      let data = {
        labels,
        datasets
      };

      let options = {
        scales: {
          yAxes: [
            {
              ticks: {
                beginAtZero: true
              }
            }
          ]
        }
      };

3) After data is loaded from a database, you can process this data and pass it to the function which creates a new Chart:

 {
            newLabels = [...]; //Data from database
            data.labels = newLabels;

            myChart = createChart({ type, data, options }); 
}

The same can be used with Datatables.

Hope it will help.

Best regards.

Hello Adam,

This is the query (limited by practical aspects):

$sql = 'SELECT * FROM compr_data, mb_regs WHERE cd_register=mbr_register ORDER BY cd_recorded DESC, cd_register LIMIT 2';
$result = pg_query($sql) or die(pg_last_error());
$row=pg_fetch_assoc($result);

Please find below var_dump($row) and a screen-shot of the resulted table:

array(16) { ["cd_azon"]=> string(5) "11378" ["cd_serial"]=> string(8) "17122509" ["cd_register"]=> string(5) "40033" ["cd_timestamp"]=> string(22) "2019-07-22 10:36:29+02" ["cd_value"]=> string(1) "0" ["cd_qualifier"]=> NULL ["cd_ts_str"]=> string(8) "5b545e2d" ["cd_recorded"]=> string(22) "2019-07-22 11:42:32+02" ["cd_seqno"]=> string(3) "240" ["mbr_azon"]=> string(1) "1" ["mbr_register"]=> string(5) "40033" ["mbr_tag"]=> string(10) "MOTOR CURR" ["mbr_desc"]=> string(44) "Display the output current of motor inverter" ["mbr_def_hex"]=> NULL ["mbr_format"]=> string(5) "000.0" ["mbr_unit"]=> string(1) "A" } array(16) { ["cd_azon"]=> string(5) "11376" ["cd_serial"]=> string(8) "17122509" ["cd_register"]=> string(5) "40110" ["cd_timestamp"]=> string(22) "2019-07-22 10:36:29+02" ["cd_value"]=> string(1) "0" ["cd_qualifier"]=> NULL ["cd_ts_str"]=> string(8) "5b545e2d" ["cd_recorded"]=> string(22) "2019-07-22 11:42:32+02" ["cd_seqno"]=> string(3) "240" ["mbr_azon"]=> string(1) "2" ["mbr_register"]=> string(5) "40110" ["mbr_tag"]=> string(8) "PRESSURE" ["mbr_desc"]=> NULL ["mbr_def_hex"]=> NULL ["mbr_format"]=> string(5) "00.00" ["mbr_unit"]=> string(3) "bar" }

This is the dump of temporary array, created in the while loop of tbody:

$text = print_r($dataTemperature, true);
var_dump($text);

string(2260) "Array ( [0] => Array ( [label] => 2019-07-22 10:36:29+02 [value] => 25.9 ) [1] => Array ( [label] => 2019-07-22 10:35:17+02 [value] => 25.9 ) [2] => Array ( [label] => 2019-07-22 10:04:57+02 [value] => 25.8 ) [3] => Array ( [label] => 2019-07-22 09:54:49+02 [value] => 25.7 ) [4] => Array ( [label] => 2019-07-22 09:34:35+02 [value] => 25.8 ) [5] => Array ( [label] => 2019-07-22 09:14:25+02 [value] => 25.8 ) [6] => Array ( [label] => 2019-07-22 08:54:12+02 [value] => 25.8 ) [7] => Array ( [label] => 2019-07-22 08:33:59+02 [value] => 25.8 ) [8] => Array ( [label] => 2019-07-22 08:23:53+02 [value] => 26.1 ) [9] => Array ( [label] => 2019-07-22 08:13:45+02 [value] => 26.1 ) [10] => Array ( [label] => 2019-07-22 08:03:39+02 [value] => 25.8 ) [11] => Array ( [label] => 2019-07-22 07:53:33+02 [value] => 25.9 ) [12] => Array ( [label] => 2019-07-22 07:12:41+02 [value] => 25.9 ) [13] => Array ( [label] => 2019-07-22 07:02:45+02 [value] => 25.9 ) [14] => Array ( [label] => 2019-07-22 06:42:54+02 [value] => 25.8 ) [15] => Array ( [label] => 2019-07-22 06:23:02+02 [value] => 25.9 ) [16] => Array ( [label] => 2019-07-22 05:53:18+02 [value] => 26.1 ) [17] => Array ( [label] => 2019-07-22 05:33:27+02 [value] => 25.7 ) [18] => Array ( [label] => 2019-07-22 05:23:30+02 [value] => 25.9 ) [19] => Array ( [label] => 2019-07-22 05:13:34+02 [value] => 25.8 ) ) "

Regards,István

Hi,

Could you tell me how your response look from the database query ?

Best,

Adam