PHP嵌套While循环不适用于mysql_fetch_assoc

Question

我测试了循环嵌套的While语句，以便：

$count1 = 0;

while ($count1 < 3) {
 $count1++;
 $count2 = 0;
 echo "count1: ".$count1."<br />";

    while ($count2 < 3) {
    $count2++;
    echo "count2: ".$count2."<br />";
    }
}

效果完美（每次循环三遍），结果如下：

count1: 1
 count2: 1
 count2: 2
 count2: 3
count1: 2
 count2: 1
 count2: 2
 count2: 3
count1: 3
 count2: 1
 count2: 2
 count2: 3

然后我尝试使用mysql_fetch_assoc（$ ContactsInterests是两行关联数组，而$ LatestNews有50行）循环进行相同的操作，即

$CI_count = 0;

while ($CI_Row = mysql_fetch_assoc($ContactsInterests)) { //loop thru interests
$CI_count++;
$LN_count = 0;
echo "CI_count: ".$CI_count."<br />";

while ($LN_Row = mysql_fetch_assoc($LatestNews)) { //loop thru news
    $LN_count++;
    echo "LN_count: ".$LN_count."<br />";

}
}

结果是：

CI_count: 1
 LN_count: 1
 LN_count: 2
 ...
 LN_count: 50
 LN_count: 51
CI_count: 2

但是LN_count的第二次迭代在哪里？我不明白为什么LN_count没有第二次增加。

帮助表示赞赏。

Answer 1

mysql_fetch_assoc对“ mysql结果”类型进行迭代。寻求每个提取的索引。您必须使用mysql_data_seek转到第一个结果，例如；

<?php

    $CI_count = 0;

    while ($CI_Row = mysql_fetch_assoc($ContactsInterests)) { //loop thru interests
        $CI_count++;
        $LN_count = 0;
        echo "CI_count: ".$CI_count."<br />";

        mysql_data_seek($LatestNews,0);
        while ($LN_Row = mysql_fetch_assoc($LatestNews)) { //loop thru news
            $LN_count++;
            echo "LN_count: ".$LN_count."<br />";

        }
    }