WordPress プラグインに Q&A 機能を追加する方法

CREATE TABLE wp_questions (
    id INT AUTO_INCREMENT PRIMARY KEY,
    question VARCHAR(255),
    answer TEXT,
    user_id INT,
    create_date TIMESTAMP DEFAULT CURRENT_TIMESTAMP
);

function create_question_table() {
    global $wpdb;
    $table_name = $wpdb->prefix . 'questions';
    $charset_collate = $wpdb->get_charset_collate();
    
    $sql = "CREATE TABLE $table_name (
        id INT AUTO_INCREMENT PRIMARY KEY,
        question VARCHAR(255),
        answer TEXT,
        user_id INT,
        create_date TIMESTAMP DEFAULT CURRENT_TIMESTAMP
    ) $charset_collate;";
    
    require_once( ABSPATH . 'wp-admin/includes/upgrade.php' );
    dbDelta( $sql );
}

<?php
/*
Template Name: Q&A Template
*/

get_header();
?>

<div id="primary" class="content-area">
    <main id="main" class="site-main" role="main">

        <?php while ( have_posts() ) : the_post(); ?>
        
            <article id="post-<?php the_ID(); ?>" <?php post_class(); ?>>
                <header class="entry-header">
                    <h1 class="entry-title"><?php the_title(); ?></h1>
                </header>

                <div class="entry-content">
                    <?php the_content(); ?>
                </div>
            </article>
            
        <?php endwhile; ?>

        <?php
        global $wpdb;
        $table_name = $wpdb->prefix . 'questions';
        $questions = $wpdb->get_results( "SELECT * FROM $table_name ORDER BY create_date DESC" );

        foreach ( $questions as $question ) {
            echo '<h2>' . $question->question . '</h2>';
            echo '<p>' . $question->answer . '</p>';
        }
        ?>

    </main>
</div>

<?php
get_sidebar();
get_footer(); 
?>

<form action="" method="post">
    <label for="question">问题：</label>
    <input type="text" name="question" id="question">
    <input type="submit" value="提交问题">
</form>

<?php
if ( isset( $_POST['question'] ) && $_POST['question'] != '' ) {
    global $wpdb;
    $table_name = $wpdb->prefix . 'questions';
    $question = sanitize_text_field( $_POST['question'] );
    $user_id = get_current_user_id();
    
    $wpdb->insert( $table_name, array(
        'question' => $question,
        'user_id' => $user_id
    ) );
}
?>

<h2>回答问题：</h2>

<form action="" method="post">
    <textarea name="answer"></textarea>
    <input type="submit" value="提交答案">
</form>

<?php
if ( isset( $_POST['answer'] ) && $_POST['answer'] != '' ) {
    global $wpdb;
    $table_name = $wpdb->prefix . 'questions';
    $answer = sanitize_textarea_field( $_POST['answer'] );
    $question_id = 1; // 假设这是问题的ID
    
    $wpdb->update( $table_name, array(
        'answer' => $answer
    ), array(
        'id' => $question_id
    ) );
}
?>