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wp_upgrade()

Runs WordPress Upgrade functions.

Description

Upgrades the database if needed during a site update.

Source

File: wp-admin/includes/upgrade.php 

function wp_upgrade() {
		global $wp_current_db_version, $wp_db_version, $wpdb;

		$wp_current_db_version = __get_option( 'db_version' );

		// We are up to date. Nothing to do.
		if ( $wp_db_version == $wp_current_db_version ) {
			return;
		}

		if ( ! is_blog_installed() ) {
			return;
		}

		wp_check_mysql_version();
		wp_cache_flush();
		pre_schema_upgrade();
		make_db_current_silent();
		upgrade_all();
		if ( is_multisite() && is_main_site() ) {
			upgrade_network();
		}
		wp_cache_flush();

		if ( is_multisite() ) {
			update_site_meta( get_current_blog_id(), 'db_version', $wp_db_version );
			update_site_meta( get_current_blog_id(), 'db_last_updated', microtime() );
		}

		/**
		 * Fires after a site is fully upgraded.
		 *
		 * @since 3.9.0
		 *
		 * @param int $wp_db_version         The new $wp_db_version.
		 * @param int $wp_current_db_version The old (current) $wp_db_version.
		 */
		do_action( 'wp_upgrade', $wp_db_version, $wp_current_db_version );
	}

Uses

Uses Description
wp-includes/ms-site.php: update_site_meta()

Updates metadata for a site.
wp-admin/includes/upgrade.php: wp_check_mysql_version()

Checks the version of the installed MySQL binary.
wp-admin/includes/upgrade.php: pre_schema_upgrade()

Runs before the schema is upgraded.
wp-admin/includes/upgrade.php: make_db_current_silent()

Updates the database tables to a new schema, but without displaying results.
wp-admin/includes/upgrade.php: upgrade_network()

Executes network-level upgrade routines.
wp-admin/includes/upgrade.php: wp_upgrade

Fires after a site is fully upgraded.
wp-includes/cache.php: wp_cache_flush()

Removes all cache items.
wp-includes/load.php: is_multisite()

If Multisite is enabled.
wp-includes/load.php: get_current_blog_id()

Retrieve the current site ID.
wp-includes/functions.php: is_main_site()

Determine whether a site is the main site of the current network.
wp-includes/functions.php: is_blog_installed()

Determines whether WordPress is already installed.
wp-includes/plugin.php: do_action()

Execute functions hooked on a specific action hook.

Changelog

Version Description
2.1.0 Introduced.

© 2003–2019 WordPress Foundation
Licensed under the GNU GPLv2+ License.
https://developer.wordpress.org/reference/functions/wp_upgrade