因为当每个复选框选择多个类别时，数据库中仅显示一个类别

如何解决因为当每个复选框选择多个类别时，数据库中仅显示一个类别

我目前正在使用php和mysql创建一个小型博客，发生的事情是，当我创建新的POST或发布时，我需要选择几类帖子。我设法创建类别系统，但选择多个时，仅1在数据库中被示出。

如您所见，我选择了几个类别，但是在查看Mysql时，在这种情况下，仅选择了Adventure类别。

代码：create.php

   <form action="create.php" method="post">
      <div class="input-group">
        <label>Nombre</label>
        <input type="text" name="title" value="<?php echo $title; ?>" class="text-input">
      </div>
    <div class="input-group">
        <label>Body</label>
        <input type="text" name="body" value="<?php echo $body; ?>" class="text-input">
      </div>
        
      <div class="box">
            <?php foreach ($categorias as $key => $categoria): ?>
            <?php if(!empty($topic) && $topic == $topic['id']): ?>
            
            
                <input id="one"  selected value="<?php echo $categoria['id']; ?>" type="checkbox" name="topic_id">
                <span class="check"></span>
                <label for="one"><?php echo $categoria['name']; ?></label>                                                
            <?php else: ?>
            
                <input id="one"  selected value="<?php echo $categoria['id']; ?>" type="checkbox" name="topic_id">
                <span class="check"></span>
                <label for="one"><?php echo $categoria['name']; ?></label>
            
            <?php endif; ?>
            

            
            <?php endforeach; ?>
      </div>

代码：posts.php

<?php 

include($_SERVER['DOCUMENT_ROOT'].'/app/database/db.php');
include($_SERVER['DOCUMENT_ROOT'].'/app/helpers/validatePost.php');

$table = 'posts';
$categorias = selectAll('categorias');

$errors = array();
$id = '';
$title = '';
$body = '';
$topic_id = '';

$posts = selectAll($table);


if (isset($_POST['add-post'])) {
    $errors = validatePost($_POST);
    
    if (count($errors) === 0){
        unset($_POST['add-post']);
        $post_id = create($table,$_POST);
        $_SESSION['message'] = 'Capitulo creado correctamente';
        $_SESSION['type'] = 'success';
        header('location: ../../admin/posts/index.php');
        exit();
    } else {
        $title = $_POST['title'];
        $body = $_POST['body'];
        $topic = $_POST['topic_id'];
    }
}

if (isset($_GET['id'])){
    $id = $_GET['id'];
    $post = selectOne($table,['id' => $id]);
    $id = $post['id'];
    $title = $post['title'];
    $body = $post['body'];
    $topic = $post['topic_id'];
}

if (isset($_GET['del_id'])){
    $id = $_GET['del_id'];    
    $count = delete($table,$id);
    $_SESSION['message'] = 'Capitulo eliminado correctamente';
    $_SESSION['type'] = 'success';
    header('location: ../../admin/posts/index.php');
    exit();
}

if (isset($_POST['update-post'])){
    $errors = validateEdit($_POST); 
    
    if (count($errors) === 0){
        $id = $_POST['id'];
        unset($_POST['update-post'],$_POST['id']);
        $post_id = update($table,$id,$_POST);
        $_SESSION['message'] = 'Genero actualizado correctamente';
        $_SESSION['type'] = 'success';
        header('location: ../../admin/topics/index.php');
        exit();        
    } else {
        $id = $_POST['id'];
        $title = $_POST['title'];
        $body = $_POST['body'];
        $topic = $_POST['topic_id'];
}
} 
?>

代码：topics.php

<?php 

include($_SERVER['DOCUMENT_ROOT'].'/app/database/db.php');
include($_SERVER['DOCUMENT_ROOT'].'/app/helpers/validateCategoria.php');

$table = 'categorias';

$errors = array();
$id = '';
$name = '';

$categorias = selectAll($table);


if (isset($_POST['add-topic'])) {
    $errors = validateCategoria($_POST);
    
    if (count($errors) === 0){
        unset($_POST['add-topic']);
        $topic_id = create($table,$_POST);
        $_SESSION['message'] = 'Genero creado correctamente';
        $_SESSION['type'] = 'success';
        header('location: ../../admin/topics/index.php');
        exit();
    } else {
        $name = $_POST['name'];
    }
}

if (isset($_GET['id'])){
    $id = $_GET['id'];
    $categoria = selectOne($table,['id' => $id]);
    $id = $categoria['id'];
    $name = $categoria['name'];
}

if (isset($_GET['del_id'])){
    $id = $_GET['del_id'];    
    $count = delete($table,$id);
    $_SESSION['message'] = 'Genero eliminado correctamente';
    $_SESSION['type'] = 'success';
    header('location: ../../admin/topics/index.php');
    exit();
}

if (isset($_POST['update-topic'])){
    $errors = validateCategoria($_POST); 
    
    if (count($errors) === 0){
        $id = $_POST['id'];
        unset($_POST['update-topic'],$_POST['id']);
        $topic_id = update($table,$_POST);
        $_SESSION['message'] = 'Genero actualizado correctamente';
        $_SESSION['type'] = 'success';
        header('location: ../../admin/topics/index.php');
        exit();        
    } else {
        $id = $_POST['id'];
        $name = $_POST['name'];
}
} 
?>    

我需要创建选择多个复选框时，这些在数据库例如注册创建发布时调用

海洋|分类：示例1，示例2

所有类别都显示在数据库中，请有人可以帮助我

解决方法

您需要将name="topic_id"更改为name="topic_id[]"，以便将其视为数组，并且服务器将接受该输入的多个值。