wordpress函数delete_post_meta()用法示例

delete_post_meta( int $post_id,  string $meta_key,  mixed $meta_value = '' )

Remove metadata matching criteria from a post.

描述

You can match based on the key, or key and value. Removing based on key and value, will keep from removing duplicate metadata with the same key. It also allows removing all metadata matching key, if needed.

参数

$post_id

(int)
(Required)
Post ID.

$meta_key

(string)
(Required)
Metadata name.

$meta_value

(mixed)
(Optional)
Metadata value. Must be serializable if non-scalar.

Default value: ”

返回值

(bool) True on success, false on failure.

源代码

File: wp-includes/post.php

function delete_post_meta( $post_id, $meta_key, $meta_value = '' ) {
	// Make sure meta is added to the post, not a revision.
	if ( $the_post = wp_is_post_revision($post_id) )
		$post_id = $the_post;

	return delete_metadata('post', $post_id, $meta_key, $meta_value);
}

更新日志

相关函数

Uses

• wp-includes/revision.php:
  wp_is_post_revision()
• wp-includes/meta.php:
  delete_metadata()

Used By

• wp-includes/class-wp-customize-nav-menus.php:
  WP_Customize_Nav_Menus::save_nav_menus_created_posts()
• wp-admin/custom-header.php:
  Custom_Image_Header::ajax_header_remove()
• wp-includes/functions.php:
  wp_scheduled_delete()
• wp-includes/class-wp-embed.php:
  WP_Embed::delete_oembed_caches()
• wp-includes/post.php:
  set_post_thumbnail()
• wp-includes/post.php:
  delete_post_thumbnail()
• wp-includes/post.php:
  wp_check_for_changed_slugs()
• wp-includes/post.php:
  wp_delete_attachment()
• wp-includes/post.php:
  wp_update_attachment_metadata()
• wp-includes/post.php:
  wp_untrash_post_comments()
• wp-includes/post.php:
  wp_insert_post()
• wp-includes/post.php:
  wp_delete_post()
• wp-includes/post.php:
  wp_untrash_post()
• wp-includes/post.php:
  update_attached_file()
• wp-includes/nav-menu.php:
  wp_update_nav_menu_item()

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   Contributed by Codex

   Default Usage

   
   <?php delete_post_meta(76, 'my_key', 'Steve'); ?>
   
   

Other Examples
Let’s assume we had a plugin that added some meta values to posts, but now when we are uninstalling the plugin, we want to delete all the post meta keys that the plugin added. Assuming the plugin added the keys 相关函数 _posts and post_inspiration.

To delete all the keys use delete_post_meta_by_key( $post_meta_key ). This would be added to the “uninstall” function:

<?php delete_post_meta_by_key( '相关函数 _posts' ); ?>

Or, if you wanted to delete all the keys except where post_inspiration was “Sherlock Holmes”:

<?php
$allposts = get_posts( 'numberposts=-1&post_type=post&post_status=any' );

foreach( $allposts as $postinfo ) {
	delete_post_meta( $postinfo->ID, '相关函数 _posts' );
	$inspiration = get_post_meta( $postinfo->ID, 'post_inspiration' );
	foreach( $inspiration as $value ) {
		if( 'Sherlock Holmes' !== $value )
			delete_post_meta( $postinfo->ID, 'post_inspiration', $value );
	}
}
?>

Or maybe post number 185 was just deleted, and you want to remove all 相关函数 _posts keys that reference it:

<?php
  $allposts = get_posts( 'numberposts=-1&post_type=post&post_status=any' );

  foreach( $allposts as $postinfo ) {
    delete_post_meta( $postinfo->ID, '相关函数 _posts', '185' );
  }
?>