以分钟为单位计算PHP中的DateDiff [关闭]

<?php

$sql_apr = " SELECT SUM ( meter * minute ) FROM table";
$rs_apr = @mysql_query($sql_apr);
$total_apr = @mysql_fetch_array($rs_apr);
$try4 = $total_apr['SUM(meter * minute'];

while ($rs_t = @mysql_fetch_array($rs_t)) {
    $minute = '';

    $sql_t = "SELECT DATEDIFF(MINUTE,'e_date e_time','s_date s_time') AS minute";
    $rs_t = @mysql_query($sql_t);
    $minute = $rs_t['minute'];
}

?>

You are looking at the wrong result:

$rs_t=@mysql_query($sql_t);
$minute = $total_t['minute'];

should be

$rs_t=@mysql_query($sql_t);
$minute = $rs_t['minute'];
//         ^ use the rs_t result, not the result from the first query

You are also result the variable that you are looping on. I highly doubt that this while loop will ever end. You are looping on the result from $rs_t and then you reassign $rs_t inside the loop.

why don't you do this in correct order

$query = "SELECT DATEDIFF(MINUTE,'e_date e_time','s_date s_time') AS minute";
$results = @mysql_query($query);
$row = @mysql_fetch_array($results);
$minute = $row['minute'];

print_r($minute);

$sql_apr = " SELECT SUM ( meter * " . $minute . " ) AS my_sum FROM table";
$rs_apr = @mysql_query($sql_apr);
$total_apr = @mysql_fetch_array($rs_apr);
$try4 = $total_apr['my_sum']; 

You try to get result (in while) before you run query.

edit:

$query = "SELECT TIMESTAMPDIFF(MINUTE,'s_date s_time','e_date e_time') AS minute";