php - 动态的 with PHP & MySQL Error</h1> <div id="body"><p>I Am trying to get a custom title on my Webpage. I want to request it from a MySQL Database. I've read about it for about an Hour now And cannot find an answer that I had an us</a></h1> <div class="ml12 aside-cta flex--item print:d-none sm:ml0 sm:mb12 sm:order-first sm:as-end"> <a href="https://stackoverflow.com/questions/ask" target="_blank" class="ws-nowrap s-btn s-btnprimary">问问题</a></div> </div> <div class="d-flex fw-wrap pb8 mb16 bb bc-black-075"> <div class="flex--item ws-nowrap mr16 mb8"> <span class="fc-light mr2"></span> </div> <div class="flex--item ws-nowrap mr16 mb8" title="2022-04-17 15:46:40Z"> <span class="fc-light mr2">问问题</span> <time itemprop="dateCreated" datetime="2013-08-31T16:23:18.877">2013-08-31T16:23:18.877</time> </div> <div class="flex--item ws-nowrap mb8" title="Viewed 6 times"> <span class="fc-light mr2"></span> 161 次 </div> </div> <div id="mainbar" role="main" aria-label="question and answers"> <div class="question" data-questionid="4" data-position-on-page="0" data-score="763" id="question"> <div class="post-layout"> <div class="votecell 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tagged 'mysqli'" rel="tag">mysqli</a> </div> </div> </div> </div> <span class="d-none" itemprop="commentCount">4</span> </div> </div> <div class="js-zone-container zone-container-responsive"> <div id="dfp-isb" class="everyonelovesstackoverflow everyonelovesinline-sidebar mx-auto" style="min-height: auto; height: auto; display: none;"></div> <div class="js-report-ad-button-container mx-auto" style="width: 300px"></div> </div> <div id="answers"> <a name="tab-top"></a> <div id="answers-header"> <div class="answers-subheader d-flex ai-center mb8"> <div class="flex--item fl1"> <h2 class="mb0" data-answercount=""> 1 回答 <span style="display:none;" itemprop="answerCount">1</span> </h2> </div> </div> </div> <a name="7"></a> <div id="answer-7" class="answer js-answer accepted-answer" data-answerid="7" data-parentid="4" data-score="506" data-position-on-page="1" data-highest-scored="1" data-question-has-accepted-highest-score="1" itemprop="suggestedAnswer" itemscope="" itemtype="https://schema.org/Answer"> <div class="post-layout"> <div class="votecell post-layout--left"> <div class="js-voting-container d-flex jc-center fd-column ai-stretch gs4 fc-black-200" data-post-id="7"> <button class="js-vote-up-btn flex--item s-btn s-btnunset c-pointer " data-controller="s-tooltip" data-s-tooltip-placement="right" aria-pressed="false" aria-label="Up vote" data-selected-classes="fc-theme-primary" data-unselected-classes="" aria-describedby="--stacks-s-tooltip-dgvag2l3"> <svg aria-hidden="true" class="svg-icon iconArrowUpLg" width="36" height="36" viewBox="0 0 36 36"><path d="M2 25h32L18 9 2 25Z"></path></svg> </button><div id="--stacks-s-tooltip-dgvag2l3" class="s-popover s-popovertooltip pe-none" aria-hidden="true" role="tooltip">This answer is useful<div class="s-popover--arrow"></div></div> <div class="js-vote-count flex--item d-flex fd-column ai-center fc-black-500 fs-title" itemprop="upvoteCount" data-value="0"> 0 </div> <button class="js-vote-down-btn flex--item s-btn s-btnunset c-pointer " data-controller="s-tooltip" data-s-tooltip-placement="right" aria-pressed="false" aria-label="Down vote" data-selected-classes="fc-theme-primary" data-unselected-classes="" aria-describedby="--stacks-s-tooltip-gn8ppsfv"> <svg aria-hidden="true" class="svg-icon iconArrowDownLg" width="36" height="36" viewBox="0 0 36 36"><path d="M2 11h32L18 27 2 11Z"></path></svg> </button> </div> </div> <div class="answercell post-layout--right"> <div class="s-prose js-post-body" itemprop="text"> <p>您可能需要阅读有关<a href="http://www.php.net/manual/en/book.mysqli.php" rel="nofollow">MySQL 改进扩展</a>的更多信息。</p> <p>这里有一些提示可以帮助您：</p> <ol> <li><p>您正在混合程序 MySQLi ( <code>mysqli_connect()</code>) 和 OO 风格的 MySQLi ( <code>$db->query()</code>)。尝试连接：<code>$db = new mysqli('localhost', 'my_user', 'my_password', 'my_db');</code></p></li> <li><p>您忘记设置第<code>$id</code>3 行使用的值：<code>$sql_title = "SELECT title FROM posts WHERE post_id='$id'";</code></p></li> <li><p>这可能是您的错误：<code><link href="./includes/db_connect.php"></code></p></li> </ol> <p>进一步查看您的代码，我们可能会在这里遇到问题：</p> <pre><code>$query_title = $db->query($sql_title); $row = $query_title->fetch_object(); $postTitle = $query_title; </code></pre> <p>请注意，它<code>$query_title</code>包含对数据库的查询，该查询返回 mysqli 结果。您正在尝试将其分配给名为的变量<code>$postTitle</code>，稍后您将<code>echo</code>在下面编辑该变量。</p> <p>尝试将上面的内容更改为：</p> <pre><code>$query_title = $db->query($sql_title); $row = $query_title->fetch_object(); $postTitle = $row->title; </code></pre> <p>为了让生活更简单，您实际上可以使用<code>fetch_assoc()</code>，这应该足以供您使用。如果可以，请阅读有关<a href="http://www.php.net/manual/en/book.mysqli.php" rel="nofollow">MySQLi 手册</a>的更多信息并查看示例。</p> </div> <div class="mt24"> <div class="user-action-time" style="color:#999;text-align:right;">于 2013-08-31T16:58:34.007 回答</div> </div> </div> </div> </div></div> </div> <div id="sidebar" class="show-votes" role="complementary" aria-label="sidebar"> <div class="module sidebar-related"> <h4 id="h-related">Related</h4> <div class="related 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