I have a basic table with columns:
If the unique column doesn't exist, INSERT the row, otherwise UPDATE the row....
INSERT INTO pages (name, etc)
VALUES
'bob',
'randomness'
ON DUPLICATE KEY UPDATE
name = VALUES(name),
etc = VALUES(etc)
The problem is that if it performs an UPDATE, the auto_increment value on the id column goes up. So if a whole bunch of UPDATES are performed, the id auto_increment goes through the roof.
Apparently it was a bug: http://bugs.mysql.com/bug.php?id=28781
...but I'm using InnoDB on mySQL 5.5.8 on shared hosting.
Other people having issues with no solution years ago: prevent autoincrement on MYSQL duplicate insert and Why does MySQL autoincrement increase on failed inserts?
Ideas on a fix? Have I maybe structured the database incorrectly somehow?
******EDIT****: It appears adding innodb_autoinc_lock_mode = 0 to your my.ini file fixes the problem but what options do I have for shared hosting?
******EDIT 2******: OK, I think my only option is to change to MyISAM as the storage engine. Being a mega mySQL newbie, I hope that doesn't cause many issues. Yeah?
I don't think there is a way to bypass this behaviour of INSERT ... ON DUPLICTE KEY UPDATE
.
You can however put two statements, one UPDATE
and one INSERT
, in one transaction:
START TRANSACTION ;
UPDATE pages
SET etc = 'randomness'
WHERE name = 'bob' ;
INSERT INTO pages (name, etc)
SELECT
'bob' AS name
, 'randomness' AS etc
FROM dual
WHERE NOT EXISTS
( SELECT *
FROM pages p
WHERE p.name = 'bob'
) ;
COMMIT ;