Re: MySQL Increment/Decrement

On Dec 29, 2009, at 3:10 AM, muzy <php@muzybot.de> wrote:

Hello Ben, I had the same question yesterday (but with SQLite) and there are at least 2 solutions. The first was already mentioned: UPDATE table SET value = value + 1 WHERE foo = bar; The second solution which also works is: UPDATE table SET value = (SELECT value FROM table WHERE foo = bar) + 1 WHERE foo = bar; I hope it helps. Greetings from Germany, Sebastian Ben Miller wrote:

I hope this isn't a bone-head question - Is there a MySQL query that will increment/decrement the value in an integer column with a single query - in other words, I don't have to run a SELECT query to get the value, add/subtract to/from the value, and then run an UPDATE query to store the new value? Thanks in advance. Ben

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You may run into race conditions and contention when handling auto-incrementimg this way. Best to isolate the SQL into a transaction to avoid this Bastien Sent from my iPod