Question

(see my answer below for solution – thanks for the feedback)

It’s probably something really obvious but I can’t see what’s wrong with my sql:

mysql> CREATE FUNCTION start_of_minute(
->     curdate DATE)
->   RETURNS DATE
->   DETERMINISTIC
->   SQL SECURITY INVOKER
->   BEGIN
->     DECLARE sofm DATE;
->     SET sofm = SUBDATE (
->         curdate,
->         INTERVAL SECOND(curdate) SECOND
->       );
->   RETURN sofm;
->   END //
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that 
corresponds to your MySQL server version for the right syntax to use near ');
RETURN sofm;
END' at line 11

All the more frustrating as the following works:

mysql> CREATE FUNCTION start_of_week(
->     curdate DATE,
-> first_day_of_week INTEGER)
->    RETURNS DATE
->    DETERMINISTIC
->    SQL SECURITY INVOKER
->    BEGIN
->       DECLARE sow DATE;
->       SET sow = SUBDATE(
->         curdate,
->         INTERVAL (WEEKDAY(curdate)+(7-first_day_of_week)%7) DAY
->         );
->       RETURN sow;
->    END //
Query OK, 0 rows affected (0.00 sec)

(NB there may be other ways of truncating the date at various levels – and I’d certainly be interested in hearing about them, I really want to know what’s wrong with my syntax – not a different method for calculating the start of a period).

Yes, second() is a valid function, and SECOND is a valid interval.

TIA

Answer 1

I had already considered that it was getting upset about the types – however replacing all the ‘date’ types with ‘DATETIME’ types did not resolve the problem – turns out the problem was a space between ‘SUBDATE’ and ‘(‘ – I never knew MySQL was fussy about such things!

(I’d flag this as an asnwer but SO wants me to wait a couple of days first)