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

Updates a post meta field based on the given post ID.


Description

Use the $prev_value parameter to differentiate between meta fields with the same key and post ID.

If the meta field for the post does not exist, it will be added and its ID returned.

Can be used in place of add_post_meta().


Parameters

$post_id

(int) (Required) Post ID.

$meta_key

(string) (Required) Metadata key.

$meta_value

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

$prev_value

(mixed) (Optional) Previous value to check before updating.

Default value: ''


Top ↑

Return

(int|bool) The new meta field ID if a field with the given key didn't exist and was therefore added, true on successful update, false on failure.


Top ↑

Source

File: wp-includes/post.php

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

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

Top ↑

Changelog

Version Description
1.5.0 Introduced.