致命错误：调用未定义的函数fetch_assoc（）提供什么？

Question

我试着从登录后的页面上显示数据库中的用户，但我不断收到一条错误消息：

致命错误：调用未定义功能FETCH_ASSOC（）

这里是代码：

<?php 
session_start(); ?> 

<link rel="stylesheet" href="form.css"> 
<div class="body content"> 

    <div class="welcome"> 
     <div class="alert alert-success"><?= $_SESSION['message'] ?></div> 
     <img src="<?= $_SESSION['avatar'] ?>"><br /> 
     Welcome <span class="user"><?= $_SESSION['username'] ?></span> 

     <?php 
     $mysqli = new mysqli("localhost","user","password","database"); 
     //Select queries return a resultset 
     $sql = "SELECT username, avatar FROM users"; 
     $result = $mysqli->query($sql); //$result = mysqli_result object 
     //var_dump($result); 
     ?> 

     <div id='registered'> 
     <span>All registered users:</span> 

     <?php 
     //while($row = $result->fetch_assoc()){ //returns associative array of fetched row 
     while($row = fetch_assoc($result)){ //returns associative array of fetched row 
      //echo '<pre>'; 
      //print_r($row); 
      //echo '</pre>'; 
      echo "<div class='userlist'><span>$row[username]</span>"; 
      echo "<img src='$row[avatar]'></div>"; 
     } 
     ?> 
     </div> 
    </div> 
</div> 

Answer 1

这是怎么了你这样做，你混合面向对象和程序：

while($row = $result->fetch_assoc()){ //returns associative array of fetched row 
      //echo '<pre>'; 
      //print_r($row); 
      //echo '</pre>'; 
      echo "<div class='userlist'><span>$row[username]</span>"; 
      echo "<img src='$row[avatar]'></div>"; 
     } 

Answer 2

这里是p正确脚本rocedural连接数据库：

<?php  
    $con = mysqli_connect("localhost","root","","db1"); 
    $sql = "SELECT username, avatar FROM users"; 
    $result = mysqli_query($con,$sql); 
    $row = mysqli_fetch_assoc($result); 
    echo $row["username"] . " " . $row["avatar"] . "<br>"; 
    mysqli_close($con); 
?>