24 hours = 24 values [duplicate]

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Possible Duplicate:

24 hours of values

Hello,

how do write the sql to get a value from each hour in one selected day ???

Meaning 24 values: 12,34,22,32,45,23,23 etc.

My table has 3 columns: | date (Y-m-d) | time (00:00:00) | power (int) |

I can only get 1 value at a time, and that is NOT what I want...

    <?php
$choice = (isset($_POST['choice'])) ? date("Y-m-d",strtotime($_POST['choice'])) : date("Y-m-d"); 
$con = mysql_connect("localhost","root","xxxxxxxxxx");  
if (!$con)  {  
die('Could not connect: ' . mysql_error());  
}  
mysql_select_db("inverters", $con);  
$sql = "SELECT date, power AS choice 
FROM feed 
WHERE date = '".$choice."' 
ORDER BY HOUR(time)"; 
$res =开发者_如何学Python mysql_query($sql) or die('sql='.$sql."\n".mysql_error()); 
$row = mysql_fetch_assoc($res); 
echo $row['choice'].'<br />'; 
?>

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If you use GROUP BY Hour(time) you can do aggregate calculations on that date by the hour.