add_post_meta( int $post_id, string $meta_key, mixed $meta_value, bool $unique = false )

Add meta data field to a post.


Description

Post meta data is called "Custom Fields" on the Administration Screen.


Parameters

$post_id

(int) (Required) Post ID.

$meta_key

(string) (Required) Metadata name.

$meta_value

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

$unique

(bool) (Optional) Whether the same key should not be added.

Default value: false


Return

(int|false) Meta ID on success, false on failure.


Source

File: wp-includes/post.php

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

	$added = add_metadata( 'post', $post_id, $meta_key, $meta_value, $unique );
	if ( $added ) {
		wp_cache_set( 'last_changed', microtime(), 'posts' );
	}
	return $added;
}


Changelog

Changelog
Version Description
WP-1.5.0 Introduced.