Question

我正在尝试构建一个每周轮换一条消息的表单，如果不存在新消息，则返回表中的第一条消息并循环返回。我已经包含了对我已经尝试过的粗略编辑，并且它在一定程度上起作用。当前代码的问题在于它在第一周或循环一次后无法正常工作。对此非常陌生，所以希望有人可以帮助我找到更好的方法来做到这一点。

<?php

$host = "localhost";
$user = "root";
$pass = "pass";
$db = "forms";

$conn = mysql_connect($host, $user, $pass)or die("Cannot connect." . mysql_error());
mysql_select_db($db)or die("Cannot select DB." . mysql_error());

function datediff($interval, $datefrom, $dateto, $using_timestamps = false) {
    /*
    $interval can be:
    yyyy - Number of full years
    q - Number of full quarters
    m - Number of full months
    y - Difference between day numbers
        (eg 1st Jan 2004 is "1", the first day. 2nd Feb 2003 is "33". The datediff is "-32".)
    d - Number of full days
    w - Number of full weekdays
    ww - Number of full weeks
    h - Number of full hours
    n - Number of full minutes
    s - Number of full seconds (default)
    */

    if (!$using_timestamps) {
        $datefrom = strtotime($datefrom, 0);
        $dateto = strtotime($dateto, 0);
    }
    $difference = $dateto - $datefrom; // Difference in seconds

    switch($interval) {

    case 'yyyy': // Number of full years
        $years_difference = floor($difference / 31536000);
        if (mktime(date("H", $datefrom), date("i", $datefrom), date("s", $datefrom), date("n", $datefrom), date("j", $datefrom), date("Y", $datefrom)+$years_difference) > $dateto) {
            $years_difference--;
        }
        if (mktime(date("H", $dateto), date("i", $dateto), date("s", $dateto), date("n", $dateto), date("j", $dateto), date("Y", $dateto)-($years_difference+1)) > $datefrom) {
            $years_difference++;
        }
        $datediff = $years_difference;
        break;
    case "q": // Number of full quarters
        $quarters_difference = floor($difference / 8035200);
        while (mktime(date("H", $datefrom), date("i", $datefrom), date("s", $datefrom), date("n", $datefrom)+($quarters_difference*3), date("j", $dateto), date("Y", $datefrom)) < $dateto) {
            $months_difference++;
        }
        $quarters_difference--;
        $datediff = $quarters_difference;
        break;
    case "m": // Number of full months
        $months_difference = floor($difference / 2678400);
        while (mktime(date("H", $datefrom), date("i", $datefrom), date("s", $datefrom), date("n", $datefrom)+($months_difference), date("j", $dateto), date("Y", $datefrom)) < $dateto) {
            $months_difference++;
        }
        $months_difference--;
        $datediff = $months_difference;
        break;
    case 'y': // Difference between day numbers
        $datediff = date("z", $dateto) - date("z", $datefrom);
        break;
    case "d": // Number of full days
        $datediff = floor($difference / 86400);
        break;
    case "w": // Number of full weekdays
        $days_difference = floor($difference / 86400);
        $weeks_difference = floor($days_difference / 7); // Complete weeks
        $first_day = date("w", $datefrom);
        $days_remainder = floor($days_difference % 7);
        $odd_days = $first_day + $days_remainder; // Do we have a Saturday or Sunday in the remainder?
        if ($odd_days > 7) { // Sunday
            $days_remainder--;
        }
        if ($odd_days > 6) { // Saturday
            $days_remainder--;
        }
        $datediff = ($weeks_difference * 5) + $days_remainder;
        break;
    case "ww": // Number of full weeks
        $datediff = floor($difference / 604800);
        break;
    case "h": // Number of full hours
        $datediff = floor($difference / 3600);
        break;
    case "n": // Number of full minutes
        $datediff = floor($difference / 60);
        break;
    default: // Number of full seconds (default)
        $datediff = $difference;
        break;
    }    
    return $datediff;
}


$current_date = date("d F Y");
$date_difference = datediff('ww', '1 December 2015', $current_date, false);
    $sql_count = "SELECT * FROM forms.quotes";
    $query_count = mysql_query($sql_count);

$row_count = mysql_num_rows($query_count);
$key = true;

while($key)
{
    if($row_count < $date_difference)
    {
        $date_difference = $date_difference - $row_count;
        $key = true;
    } else {
        $key = false;
    }
}


$sql = "SELECT * FROM forms.quotes WHERE id = '$date_difference'";
    $query = mysql_query($sql);
    while($row = mysql_fetch_array($query)) {

            echo "<body bgcolor='#4E2F91'><font color='#dfcd6b'><i>";
            echo $row['message'];
            echo "</i></font></body>";
    }
echo mysql_error();

?>

Answer 1

免责声明：请勿使用mysql_*个功能。请改用mysqli或PDO（在示例中）。

首先你必须为当周选择合适的报价。您可以将显示的日期存储在数据库中：

$sth = $dbh->prepare('SELECT * FROM forms.quotes WHERE WEEK(date_shown)=:week_number AND YEAR(date_shown)=:year LIMIT 1');
$sth->bindParam(':week_number', date('W'));
$sth->bindParam(':year', date('Y'));

下一步如果在第一个选择语句中找不到任何内容，则必须使用当前日期更新最早显示的引号：

UPDATE forms.quotes SET shown.date = NOW() ORDER BY shown_date ASC LIMIT 1;

重复步骤＃1 - 现在你应该得到一个结果。

如果要在select语句中操作结果（为窗帘周添加新引号并确保它将显示），可以在select子句中添加ORDER BY created_at DESC语句或类似语句。

旋转每周消息的最佳方式？

1 个答案: