on update current_timestamp with SQLite
John is correct about the default SQLite settings, this trigger leads to an infinite loop. To avoid recursion, use the WHEN clause.
Following will work even if the recursive_triggers
setting is on:
PRAGMA recursive_triggers=1; --- test
CREATE TRIGGER [UpdateLastTime]
AFTER UPDATE
ON package
FOR EACH ROW
WHEN NEW.LastUpdate < OLD.LastUpdate --- this avoid infinite loop
BEGIN
UPDATE Package SET LastUpdate=CURRENT_TIMESTAMP WHERE ActionId=OLD.ActionId;
END;
Yes, you'd need to use a trigger. (Just checking: is your posted trigger working correctly? At first glance, it looks fine to me.)
MySQL's ON UPDATE CURRENT_TIMESTAMP
is a pretty unique, single-purpose shortcut. It is what it is; this construct cannot be used similarly for any other values or for any column types other than TIMESTAMP
. (Note how this functionality is defined on the TIMESTAMP
type page instead of the CREATE TABLE
page, as this functionality is specific to TIMESTAMP
columns and not CREATE TABLE
statements in general.) It's also worth mentioning that while it's specific to a TIMESTAMP
type, SQLite doesn't even have distinct date/time types.
As far as I know, no other RDBMS offers this shortcut in lieu of using an actual trigger. From what I've read, triggers must be used to accomplish this on MS SQL, SQLite, PostgreSQL, and Oracle.
One last note for passersby:
This is not to be confused with ON UPDATE
clauses in relation to foreign key constraints. That's something entirely different, which likely all RDBMSs that support foreign key constraints have (including both MySQL and SQLite).