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

Deletes a post meta field for the given post ID.

Description

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 the key, if needed.

Parameters

$post_idintrequired
Post ID.
$meta_keystringrequired
Metadata name.
$meta_valuemixedoptional
Metadata value. If provided, rows will only be removed that match the value.
Must be serializable if non-scalar.

Default:''

Return

bool True on success, false on failure.

Source

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

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

Changelog

VersionDescription
1.5.0Introduced.

User Contributed Notes

  1. Skip to note 5 content

    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 related_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( 'related_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, 'related_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 related_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, 'related_posts', '185' );
      }
    ?>
  2. Skip to note 7 content

    Be VERY careful when using this function to delete a specific key-value pair. As stated in delete_metadata()‘s documentation, providing an empty string for $meta_value will cause the check to be skipped entirely, resulting in all keys being deleted!

    $meta_value …If specified, only delete metadata entries with this value. Otherwise, delete all entries with the specified meta_key

    To avoid accidentally deleting ALL key instances, use a short-circuit check:

    $value_to_delete = My_Class::get_value(); // may return empty string
    if ( $value_to_delete != '' && delete_metadata( 'post', 27, 'key', $value_to_delete ) ) {
     // the key-value pair was safely deleted
    }

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