woothemes / woocommerce

		/**

		 * Before updating with DBDELTA, remove any primary keys which could be modified due to schema updates.

		 */

		if ( $wpdb->get_var( "SHOW TABLES LIKE '{$wpdb->prefix}woocommerce_downloadable_product_permissions';" ) ) {

			if ( ! $wpdb->get_var( "SHOW COLUMNS FROM `{$wpdb->prefix}woocommerce_downloadable_product_permissions` LIKE 'permission_id';" ) ) {

				$wpdb->query( "ALTER TABLE {$wpdb->prefix}woocommerce_downloadable_product_permissions DROP PRIMARY KEY, ADD `permission_id` bigint(20) NOT NULL PRIMARY KEY AUTO_INCREMENT;" );

			}

		}

		if ( $wpdb->get_var( "SHOW TABLES LIKE '{$wpdb->prefix}woocommerce_tax_rate_locations';" ) ) {

			if ( $wpdb->get_var( "SHOW INDEX FROM `{$wpdb->prefix}woocommerce_tax_rate_locations` WHERE Key_name LIKE 'location_type_code';" ) ) {

			}

		}

		if ( $wpdb->get_var( "SHOW TABLES LIKE '{$wpdb->prefix}woocommerce_tax_rate_locations';" ) ) {

			if ( $wpdb->get_var( "SHOW INDEX FROM `{$wpdb->prefix}woocommerce_tax_rate_locations` WHERE Key_name LIKE 'location_type_code';" ) ) {

				$wpdb->query( "DROP INDEX `location_type_code` ON {$wpdb->prefix}woocommerce_tax_rate_locations;" );

			}

		}

		dbDelta( self::get_schema() );

	}