问题

我想为我的数据表添加下一页和上一页的链接。
如何编写查询以获取下一页和上一页的数据？

&lt;div&gt;
   &lt;a style=&quot;margin-left:5px;&quot; href=&quot;#&quot; class=&quot;previous&quot;&gt;&amp;laquo; 上一页&lt;/a&gt;
   &lt;a style=&quot;margin-left:5px;&quot; href=&quot;#&quot; class=&quot;next&quot;&gt;下一页 &amp;raquo;&lt;/a&gt;
&lt;/div&gt;

$recordsPerPage = 20;

$totalPages = ceil($totalCount / $recordsPerPage);

$page = isset($_GET[&#39;page&#39;]) ? $_GET[&#39;page&#39;] : 1;

$offset = ($page - 1) * $recordsPerPage;

$query = &quot;SELECT * FROM history&quot; . $whereClause . &quot; LIMIT &quot; .$recordsPerPage. &quot; OFFSET &quot; .$offset.&quot;;&quot;;

我希望在点击下一页时只获取前20条数据，然后显示下一批20条数据。

英文:

i want to add next and previous links for my data table.
how to write query to get data in next and prevous links data

&lt;div&gt;
   &lt;a style=&quot;margin-left:5px;&quot; href=&quot;#&quot; class=&quot;previous&quot;&gt;&amp;laquo; Previous&lt;/a&gt;
   &lt;a style=&quot;margin-left:5px;&quot; href=&quot;#&quot; class=&quot;next&quot;&gt;Next &amp;raquo;&lt;/a&gt;
&lt;/div&gt;

$recordsPerPage = 20;

$totalPages = ceil($totalCount / $recordsPerPage);

$page = isset($_GET[&#39;page&#39;]) ? $_GET[&#39;page&#39;] : 1;

$offset = ($page - 1) * $recordsPerPage;

$query = &quot;SELECT * FROM history&quot; . $whereClause . &quot; LIMIT &quot; .$recordsPerPage. &quot;OFFSET &quot; .$offset.&quot;;&quot;;

i am expecting to get data only 20 entries first when i click on next i want to show next 20 entries

答案1

得分: 3

你需要调用nextPage：

$cluster   = Cassandra::cluster()
               ->withContactPoints('127.0.0.1')
               ->build();
$session   = $cluster->connect("simplex");
$options   = array('page_size' => 5);
$rows      = $session->execute("SELECT * FROM paging_entries", $options);

while (true) {
    echo "entries in page: " . $rows->count() . "\n";

    foreach ($rows as $row) {
        echo "key: " . $row['key'] . ", value: " . $row['value'] . "\n";
    }

    if ($rows->isLastPage()) {
        break;
    }

    $rows = $rows->nextPage();
}

英文:

You'll need to call nextPage:

&lt;?php
$cluster   = Cassandra::cluster()
               -&gt;withContactPoints(&#39;127.0.0.1&#39;)
               -&gt;build();
$session   = $cluster-&gt;connect(&quot;simplex&quot;);
$options   = array(&#39;page_size&#39; =&gt; 5);
$rows      = $session-&gt;execute(&quot;SELECT * FROM paging_entries&quot;, $options);

while (true) {
    echo &quot;entries in page: &quot; . $rows-&gt;count() . &quot;\n&quot;;

    foreach ($rows as $row) {
        echo &quot;key: &quot; . $row[&#39;key&#39;] . &quot;, value: &quot; . $row[&#39;value&#39;] . &quot;\n&quot;;
    }

    if ($rows-&gt;isLastPage()) {
        break;
    }

    $rows = $rows-&gt;nextPage();
}

There are more examples here:

https://docs.datastax.com/en/developer/php-driver/1.3/features/result_paging/

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