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Php PDO Sql语句按错误顺序排列 _Php_Mysql_Sql - Fatal编程技术网

Php PDO Sql语句按错误顺序排列

Php PDO Sql语句按错误顺序排列 ,php,mysql,sql,Php,Mysql,Sql,我正在尝试从数据库获取结果并使用分页。问题是,语句中要求的降序从未适用。为什么这不起作用?如果我不添加“ORDER BY date DESC”行,它就可以正常工作,但当我添加时,它会打印错误,即我试图获取一个非对象。您的语法不太正确 用这个来代替 <?php require('db_info.php'); $recordsPerPage = 5; if (isset($_GET['page'])) $curPage = $_GET['page']; else $curPa

我正在尝试从数据库获取结果并使用分页。问题是,语句中要求的降序从未适用。为什么这不起作用?如果我不添加“ORDER BY date DESC”行,它就可以正常工作,但当我添加时,它会打印错误,即我试图获取一个非对象。

您的语法不太正确

用这个来代替

<?php 
require('db_info.php');
$recordsPerPage = 5;
if (isset($_GET['page']))
  $curPage = $_GET['page'];
else
      $curPage = 1;
  $startIndex = ($curPage-1) * $recordsPerPage;

try {
       $pdoObject = new PDO("mysql:host=$dbhost; dbname=$dbname;", $dbuser, $dbpass);
   $sql = "SELECT count(id) FROM usercom";
   $statement = $pdoObject->query($sql); 
   $record = $statement->fetch(PDO::FETCH_ASSOC);
   $pages = ceil($record['count(id)']/$recordsPerPage);

   $record=null;
   $sql = "SELECT * FROM usercom LIMIT $startIndex, $recordsPerPage ORDER BY date DESC";
   $statement = $pdoObject->query($sql);
   while ( $record = $statement->fetch(PDO::FETCH_ASSOC) ) {
   echo '<p>'.$record['date'].'<br/>'.$record['userComment'].'<br/>';
                }


   $statement->closeCursor();

   $pdoObject = null;

   } catch (PDOException $e) {

   echo 'PDO Exception: '.$e->getMessage();
    die();

   }?></p>

限制在最后,而不是在ORDER BYFatal error之前:对非对象调用成员函数fetch()打印查询并查看其外观。此外,正如马瑞克所说,在日期周围使用倒勾。@user3665011:什么没有改变?错误?还是输出?可能是限制范围不正确。“致命错误:对非对象调用成员函数fetch()”我将usercom更改为“usercom”,将date更改为“date”,但仍然..然后是PHP错误而不是MySQL查询。上面的SQL查询很好。我知道,你知道如何修复它吗?你不能对表/列名使用普通的单引号('usercom','date'),你必须使用反勾('usercom','date'))
$sql = "SELECT * FROM `usercom` ORDER BY `date` DESC LIMIT $startIndex, $recordsPerPage";