每4条记录创建列表[重复]

Question

我正在尝试创建多个记录列表，每个列表有 4 条记录，但不知道有多少条记录。但是，我无法弄清楚如何处理数学。我手动输入 $n == 5 || $n == 9 等知道它是 stipud 并且不能完全解决问题。谁能帮我处理一下。此外，只有在记录总数不能被 4 整除时，下面的列表才能正常工作。如果可以，它会在最后创建一个空白列表。

$query = "SELECT * FROM `table` WHERE `field` = $whatever";
if ($result = $con->query($query)){
$n = 1
$row_cnt = $result->num_rows;
$total_lists = round($row_cnt / 4, 0);
$current_list = 1;
echo "<ul>List $current_list of $total_lists";
    while ($row = $result->fetch_assoc()) {
    echo "<li>$row['something']</li>";
        if ($n == 5 || $n == 9 || $n == 13 || $n == 17 || $n == 21 || $n ==25 || $n ==29 || $n == 33 || $n == 37 || $n == 41 || $n == 45 || $n == 49 || $n == 53 || $n == 57 || $n == 61 || $n == 65 || $n == 69 || $n == 73 || $n == 77){
        echo "</ul>";
        $current_list = $current_list + 1;
        echo "<ul>List $current_list of $total_lists";
        }
    $n = $n + 1;
    }
echo "</ul>";
}

提前感谢您的帮助。 :)

已解决：

$query = "SELECT * FROM `table` WHERE `field` = $whatever";
if ($result = $con->query($query)){
$n = 0
$row_cnt = $result->num_rows;
$total_lists = ceil($row_cnt / 4);
$current_list = 1;
echo "<ul>List $current_list of $total_lists";
    while ($row = $result->fetch_assoc()) {
        $n++;
    echo "<li>$row['something']</li>";
        if ($row_cnt > 4) {
    if ($n % 4 === 0) {
    echo "</ul>";
    $current_list = $current_list + 1;
    echo "<ul>List $current_list of $total_lists";
        }
        }
    }
echo "</ul>";
}

Answer 1

您实际上离您可能想要做的事情并不太远，您只需要使用一个额外的工具来完成它：% 或模数运算符。

模运算符将返回除法问题的余数：

$x = 5 % 2; // 1

看看你的逻辑，当你的增量器 ($n) 减去 1 除以 4 的余数为 0 时，你需要采取行动：

if (($n - 1) % 4 === 0)
{
    //your <ul> insertion could go here.
}

这里是讨论数学运算符的 PHP 手册页的链接：

http://us1.php.net/manual/en/language.operators.arithmetic.php

Answer 2

或者，您可以在数据库结果中使用简单的array_chunk()。为其提供适当的分组（在本例中为四个），然后它们通过 foreach 循环它们。考虑这个例子：

// dummy data (values from db)
$values_from_db = array(
    array('id' => 1, 'something' => 'list1'),
    array('id' => 2, 'something' => 'list2'),
    array('id' => 3, 'something' => 'list3'),
    array('id' => 4, 'something' => 'list4'),
    array('id' => 5, 'something' => 'list5'),
    array('id' => 6, 'something' => 'list6'),
    array('id' => 7, 'something' => 'list7'),
    array('id' => 8, 'something' => 'list8'),
    array('id' => 9, 'something' => 'list9'),
);

$values_from_db = array_chunk($values_from_db, 4); // group them by four's

?>

<?php foreach($values_from_db as $key => $value): ?>
    <ul style="list-style-type: none;">
    <?php foreach($value as $index => $element): ?>
        <li><?php echo $element['id'].'.'.$element['something']; ?></li>
    <?php endforeach; ?>
    </ul>
<?php endforeach; ?>