Question

update_metadata_by_mid( string $meta_type,  int $meta_id,  string $meta_value,  string $meta_key = false )

Update meta data by meta ID

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description

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参数

$meta_type

(string) (Required) Type of object metadata is for (e.g., comment, post, or user)

$meta_id

(int) (Required) ID for a specific meta row

$meta_value

(string) (Required) Metadata value

$meta_key

(string) (Optional) you can provide a meta key to update it

Default value: false

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返回值

(bool) True on successful update, false on failure.

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源代码

File: wp-includes/meta.php

function update_metadata_by_mid( $meta_type, $meta_id, $meta_value, $meta_key = false ) {
	global $wpdb;

	// Make sure everything is valid.
	if ( ! $meta_type || ! is_numeric( $meta_id ) || floor( $meta_id ) != $meta_id ) {
		return false;
	}

	$meta_id = intval( $meta_id );
	if ( $meta_id <= 0 ) {
		return false;
	}

	$table = _get_meta_table( $meta_type );
	if ( ! $table ) {
		return false;
	}

	$column = sanitize_key($meta_type . '_id');
	$id_column = 'user' == $meta_type ? 'umeta_id' : 'meta_id';

	// Fetch the meta and go on if it's found.
	if ( $meta = get_metadata_by_mid( $meta_type, $meta_id ) ) {
		$original_key = $meta->meta_key;
		$object_id = $meta->{$column};

		// If a new meta_key (last parameter) was specified, change the meta key,
		// otherwise use the original key in the update statement.
		if ( false === $meta_key ) {
			$meta_key = $original_key;
		} elseif ( ! is_string( $meta_key ) ) {
			return false;
		}

		// Sanitize the meta
		$_meta_value = $meta_value;
		$meta_value = sanitize_meta( $meta_key, $meta_value, $meta_type );
		$meta_value = maybe_serialize( $meta_value );

		// Format the data query arguments.
		$data = array(
			'meta_key' => $meta_key,
			'meta_value' => $meta_value
		);

		// Format the where query arguments.
		$where = array();
		$where[$id_column] = $meta_id;

		/** This action is documented in wp-includes/meta.php */
		do_action( "update_{$meta_type}_meta", $meta_id, $object_id, $meta_key, $_meta_value );

		if ( 'post' == $meta_type ) {
			/** This action is documented in wp-includes/meta.php */
			do_action( 'update_postmeta', $meta_id, $object_id, $meta_key, $meta_value );
		}

		// Run the update query, all fields in $data are %s, $where is a %d.
		$result = $wpdb->update( $table, $data, $where, '%s', '%d' );
		if ( ! $result )
			return false;

		// Clear the caches.
		wp_cache_delete($object_id, $meta_type . '_meta');

		/** This action is documented in wp-includes/meta.php */
		do_action( "updated_{$meta_type}_meta", $meta_id, $object_id, $meta_key, $_meta_value );

		if ( 'post' == $meta_type ) {
			/** This action is documented in wp-includes/meta.php */
			do_action( 'updated_postmeta', $meta_id, $object_id, $meta_key, $meta_value );
		}

		return true;
	}

	// And if the meta was not found.
	return false;
}

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更新日志

Version	description
3.3.0	Introduced.

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相关函数

Uses

• wp-includes/cache.php: wp_cache_delete()
• wp-includes/formatting.php: sanitize_key()
• wp-includes/functions.php: maybe_serialize()
• wp-includes/plugin.php: do_action()
• wp-includes/wp-db.php: wpdb::update()
• wp-includes/meta.php: _get_meta_table()
• wp-includes/meta.php: sanitize_meta()
• wp-includes/meta.php: get_metadata_by_mid()
• wp-includes/meta.php: update_{$meta_type}_meta
• wp-includes/meta.php: update_postmeta
• wp-includes/meta.php: updated_{$meta_type}_meta
• wp-includes/meta.php: updated_postmeta
Show 7 more uses Hide more uses

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Used By

• wp-admin/includes/post.php: update_meta()
• wp-admin/includes/ajax-actions.php: wp_ajax_add_meta()
• wp-includes/class-wp-xmlrpc-server.php: wp_xmlrpc_server::set_custom_fields()

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User Contributed Notes