update_post_meta
update_post_meta ( $post_id, $meta_key, $meta_value, $prev_value = '' )
Parameters:- (int) post_id Post ID.
- (string) meta_key Metadata key.
- (mixed) meta_value Metadata value. Must be serializable if non-scalar.
- (mixed) prev_value Optional. Previous value to check before updating. If specified, only update existing metadata entries with this value. Otherwise, update all entries. Default empty.
Returns:- (int|bool) Meta ID if the key didn't exist, true on successful update, false on failure or if the value passed to the function is the same as the one that is already in the database.
Defined at: - Introduced in WordPress: 1.5.0
- Deprecated in WordPress: —
Description
Updates a post meta field based on the given post ID.Use the `$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().