在页面导航时更改 SQL 语句答案

【问题标题】：Change SQL Statement Upon Page Navigation在页面导航时更改 SQL 语句
【发布时间】：2018-08-23 19:15:57
【问题描述】：

我对这一切都很陌生，如果不可能，请纠正我。

我正在尝试使用此 SQL 语句显示数据：

SELECT * FROM trail101 WHERE activities IN(\'Murals\',\'Concert\',\'Theater\',\'Museums\') ORDER BY id DESC LIMIT 0, 9

它只显示我拥有的前 9 条数据，但我希望能够导航到接下来的 9 条，其中单击分页会将 SQL 语句更新为 ORDER BY id DESC LIMIT 9, 18 用于下一页和等等。我将如何编写脚本？我有以下导航代码：

<div class="w3-center w3-padding-32">
<div class="w3-bar">
  <a href="#" class="w3-bar-item w3-button w3-hover-black" class="w3-bar-item w3-button w3-hover-black">«</a>
  <a href="#" class="w3-bar-item w3-black w3-button">1</a>
  <a href="#" class="w3-bar-item w3-button w3-hover-black">2</a>
  <a href="#" class="w3-bar-item w3-button w3-hover-black">3</a>
  <a href="#" class="w3-bar-item w3-button w3-hover-black">4</a>
  <a href="#" class="w3-bar-item w3-button w3-hover-black">»</a>
</div>

【问题讨论】：

有可能，它叫分页，查一下，找到很多资源。

标签： javascript php html sql

【解决方案1】：

有一个简单的代码示例与您的分页查询，检查一下

  <html>       
   <head>
      <title>Paging Using PHP</title>
   </head>

   <body>
      <?php
         $dbhost = 'localhost:3036';
         $dbuser = 'root';
         $dbpass = 'password';

         $rec_limit = 10;
         $conn = mysql_connect($dbhost, $dbuser, $dbpass);

         if(! $conn ) {
            die('Could not connect: ' . mysql_error());
         }
         mysql_select_db('test_db');

         /* Get total number of records */
         $sql = "SELECT * FROM trail101 WHERE activities IN(\'Murals\',\'Concert\',\'Theater\',\'Museums\') ORDER BY id";
         $retval = mysql_query( $sql, $conn );

         if(! $retval ) {
            die('Could not get data: ' . mysql_error());
         }
         $row = mysql_fetch_array($retval, MYSQL_NUM );
         $rec_count = $row[0];

         if( isset($_GET{'page'} ) ) {
            $page = $_GET{'page'} + 1;
            $offset = $rec_limit * $page ;
         }else {
            $page = 0;
            $offset = 0;
         }

         $left_rec = $rec_count - ($page * $rec_limit);
         $sql = "SELECT *  ". 
            "FROM trail101 ".
            "WHERE activities IN(\'Murals\',\'Concert\',\'Theater\',\'Museums\') ORDER BY id ".
            "LIMIT $offset, $rec_limit";

         $retval = mysql_query( $sql, $conn );

         if(! $retval ) {
            die('Could not get data: ' . mysql_error());
         }

         while($row = mysql_fetch_array($retval, MYSQL_ASSOC)) {
            echo "ID :{$row['id']}  <br> ".
               "ACTIVITY NAME : {$row['activity_name']} <br> ".
               "--------------------------------<br>";
         }

         if( $page > 0 ) {
            $last = $page - 2;
            echo "<a href = \"$_PHP_SELF?page = $last\">Last 10 Records</a> |";
            echo "<a href = \"$_PHP_SELF?page = $page\">Next 10 Records</a>";
         }else if( $page == 0 ) {
            echo "<a href = \"$_PHP_SELF?page = $page\">Next 10 Records</a>";
         }else if( $left_rec < $rec_limit ) {
            $last = $page - 2;
            echo "<a href = \"$_PHP_SELF?page = $last\">Last 10 Records</a>";
         }

         mysql_close($conn);
      ?>

   </body>
</html>

【讨论】：