myPHAdmin give different results than PHP select
Greetings,
I'm a newbie so please bear with me. I am working with an RPi and 'inserting' into a MySQL database from Python. That part works fine.
Forgive me if I give you too much info but I want things to be in context so you can understand my configuration.
Using my RPi, (Raspberry Pi 3 B) I read temp, humidity and barometric pressure sensors and insert them into my DB called 'weather'. I then query a table called 'WEATHER_MEASUREMENTS' to display various data in a website hosted locally using lighttpd.
One of the things I wish to display is the last 24 hours of barometric pressure.
I currently insert temperature, humidity and barometric pressure into my DB once every 10 minutes. In order to display weather trends I wish to show barometric pressure readings over 24 hours. Since I take 6 readings per hour, I wanted limit it to ten readings over 24 hours, equally spaced. I took this to be equivalent to 'mod 14'. I wish to display to two columns, 'AIR_PRESSURE' and 'CREATED'. CREATED is a 'timestamp' column.
I have two files I work with; my index.php and readings.html.php. At the end of the index.php file is an 'include' line that reads: include 'readings.html.php';
My initial query is done in the index.php and looks like this:
$result = mysqli_query($link, 'Select ID, CREATED, DATE(CREATED), AIR_PRESSURE
FROM WEATHER_MEASUREMENT WHERE mod(ID,14) = 0 GROUP BY CREATED ORDER BY ID DESC LIMIT 10');
if (!$result)
{
$error = 'Error fetching date : ' . mysqli_error($link);
include 'error.html.php';
exit();
}
while ($row = mysqli_fetch_array($result))
{
$prevdaypress[] = $row['AIR_PRESSURE'];
$prevdaytime[] = $row['CREATED'];
}
$testarray=array_combine($prevdaypress, $prevdaytime);
Then in my 'readings.html.php' I have this:
<?php foreach ($testarray as $prevdaystuff): ?>
<?php echo ($prevdaystuff)?><br>
<?php endforeach; ?>
And this is my output on my web page:
2017-05-01 17:58:33
2017-05-01 15:37:53
2017-05-01 13:17:19
2017-05-01 10:56:37
2017-05-01 08:35:47
2017-05-01 06:14:54
2017-04-30 23:13:43
2017-04-30 20:53:19
There are two things to note; the barometric pressure isn't in the list, which should be there from the line, '$prevdaypress[] = $row['AIR_PRESSURE'];'.
Also, notice the large gap between, '2017-04-30 23:13:43' and '2017-05-01 06:14:54'. The gap should only be a max of about 2.5 hours if you do the math.
I've tried a bunch of different combinations of this query, etc. and sometimes I have a date from April mixed in between two 'May dates'.
I hope I've provide enough information. I wanted to give a good idea of what I was doing and what I wanted to achieve. Your help is appreciated!