Altering timestamp

[code green]

I'm pretty sure this should throw an error as
"you cannot update a table and select from the same table in a subquery" (MySql Manual)

ewise_slice.slice_timestamp

What query browser are you using, Is error reporting / logging switched on?
Also are you sure the subquery returns only one value

[dbrewerton]

I modified my query to the way you've suggested. I ran it through a query analyzer and when it runs even with static variables, it gives me a null result. I am using the one that comes with MySQL Administrator.

[code green]

How have you modified the query? Because the syntax was actually illegal

[dbrewerton]

Yes, I re-wrote the SP like this so I'm only impacting the very last record. It currently reads as follows:

############### ####
delimiter ;

DROP PROCEDURE IF EXISTS `fixmytimes`;

DELIMITER $$
CREATE PROCEDURE `fixmytimes`(IN RealTime text, IN countit INT)
BEGIN

declare time1 TIMESTAMP;
declare Timevar TIMESTAMP;
declare firstrec INT default 1;
declare mycount INT default 1;
declare fixedtime TIMESTAMP;
declare maxslice INT;

SELECT MAX(slice_id) as maxslice, slice_timestamp AS time1 from ewise_slice;
SELECT timestampdiff(M INUTE,time1,Rea lTime) INTO Timevar;
SELECT maxslice - countit INTO firstrec;

while mycount < countit DO

SELECT date_Add(time1, INTERVAL Timevar MINUTE) AS fixedtime;
UPDATE ewise_slice set slice_timestamp = fixedtime where slice_id = firstrec;

set mycount = mycount+1;
set firstrec = firstrec+1;
END WHILE;

END
$$

############### #####

[code green]

I cannot explain the NULL result.
All I can suggest is test each query seperately to find the failing query.
Then breakdown that query into simpler steps using one value at a time.
This is called debugging