PHP MySQL WHERE SUM WHERE SUBSTRING

Question

有点不明白!我想在以下输入字段 stamp_updated，2014-01-28 17:31:02 下的数据库中创建一个查询。

现在我只想拥有标签为 28 的记录:

$ qry = "SELECT SUM (bytes) A​​S total FROM acct_v4 WHERE SUBSTRING (stamp_updated, 9,10) = '28 '";

不幸的是，我没有得到任何输出，这是 SUBSTRING？

附言: 应该是什么:我记录端口流量，让他写在数据库里，想有每日统计。

完成问新

现在我站在逻辑问题的前面......当我尝试将其作为日常交通花费时，我该如何最好地表达它？

2014-01-26: xx traffic 2014-01-27: xx traffic 2014-01-28: xx traffic

<?php
error_reporting(E_ALL);
ini_set('display_errors', 1);
?>
<?php 

function formatBytes($size, $precision = 2)
{
    $base = log($size) / log(1024);
    $suffixes = array('', 'k', 'MB', 'GB', 'TB');   

    return round(pow(1024, $base - floor($base)), $precision) . $suffixes[floor($base)];
}


$db=mysql_connect("localhost","traffic","....."); 
mysql_select_db("traffic",$db);
$qry = "SELECT SUM(bytes) AS total FROM acct_v4 
          WHERE SUBSTRING(stamp_updated,9,2) = '28' ";


$select = mysql_query($qry);
$result = mysql_fetch_array($select);


echo 'Summe: '.formatBytes($result['total']);  
//echo $result['total'];


?>

Answer 1

你可以试试

SELECT SUM (bytes) AS total FROM acct_v4 WHERE DAY(stamp_updated) = 28;