Initial

Post_Meta/meta_boxes/add_post_meta_to_separate_table/index.php

@@ -0,0 +1,96 @@
+<?php 
+
+function create_custom_meta_table() {
+    global $wpdb;
+    $table_name = $wpdb->prefix . 'custom_meta_table'; // Table name
+
+    // Set the charset and collation
+    $charset_collate = $wpdb->get_charset_collate();
+
+    // SQL to create the table
+    $sql = "CREATE TABLE $table_name (
+        id mediumint(9) NOT NULL AUTO_INCREMENT,
+        post_id bigint(20) NOT NULL,
+        custom_field_value varchar(255) DEFAULT '' NOT NULL,
+        PRIMARY KEY (id),
+        KEY post_id (post_id)
+    ) $charset_collate;";
+
+    // Include the upgrade file which contains the dbDelta() function
+    require_once(ABSPATH . 'wp-admin/includes/upgrade.php');
+
+    // Run the SQL to create the table
+    dbDelta($sql);
+}
+register_activation_hook(__FILE__, 'create_custom_meta_table');
+
+
+function add_custom_meta_box() {
+    add_meta_box(
+        'custom_meta_box', // ID for the meta box
+        'Custom Meta Box', // Title of the meta box
+        'custom_meta_box_callback', // Callback function to display the content
+        'post', // Post type (you can add other types like 'page' or custom post types)
+        'normal', // Context (where the meta box appears: normal, side, advanced)
+        'high' // Priority (high, core, default, low)
+    );
+}
+add_action('add_meta_boxes', 'add_custom_meta_box');
+
+
+
+function custom_meta_box_callback($post) {
+    // Add nonce field for security
+    wp_nonce_field('custom_meta_box_nonce', 'meta_box_nonce');
+
+    // Get the current value of the custom field from the database (if any)
+    $custom_value = get_post_meta($post->ID, '_custom_field', true);
+
+    // Display the form field
+    echo '<label for="custom_field">Custom Field</label>';
+    echo '<input type="text" id="custom_field" name="custom_field" value="' . esc_attr($custom_value) . '" />';
+}
+
+
+
+function save_custom_meta_data($post_id) {
+    // Check if it's an autosave or if the nonce is not valid
+    if (defined('DOING_AUTOSAVE') && DOING_AUTOSAVE) return $post_id;
+    if (!isset($_POST['meta_box_nonce']) || !wp_verify_nonce($_POST['meta_box_nonce'], 'custom_meta_box_nonce')) return $post_id;
+
+    // Check if the user has permission to edit the post
+    if ('post' != $_POST['post_type'] || !current_user_can('edit_post', $post_id)) return $post_id;
+
+    // Get the posted value
+    $custom_value = isset($_POST['custom_field']) ? sanitize_text_field($_POST['custom_field']) : '';
+
+    // Insert or update the custom value in the custom table
+    global $wpdb;
+    $table_name = $wpdb->prefix . 'custom_meta_table';
+
+    // Check if this post already has an entry in the custom table
+    $existing_entry = $wpdb->get_var($wpdb->prepare("SELECT id FROM $table_name WHERE post_id = %d", $post_id));
+
+    if ($existing_entry) {
+        // Update the existing row
+        $wpdb->update(
+            $table_name,
+            array('custom_field_value' => $custom_value),
+            array('post_id' => $post_id),
+            array('%s'),
+            array('%d')
+        );
+    } else {
+        // Insert a new row
+        $wpdb->insert(
+            $table_name,
+            array('post_id' => $post_id, 'custom_field_value' => $custom_value),
+            array('%d', '%s')
+        );
+    }
+
+    return $post_id;
+}
+add_action('save_post', 'save_custom_meta_data');
+
+