MySQL: Increment an exisitng value

Posted February 24, 2007 by Quinn McHenry in MySQL

This slick MySQL syntax allows you to increment or decrement an existing number in a table without first having to read the value. This is a nice way to increment an access counter.


To increment the value ‘counter’ by one for the row in table ‘images’ where ‘image_id’ is ’15’, use:

UPDATE images SET counter=counter+1 WHERE image_id=15

To decrement the value, use ‘counter=counter-1’ instead. Incrementing or decrementing by other values (or using whatever valid arithmetic arm flexing you need) will work, too.

 

About Quinn McHenry

Quinn was one of the original co-founders of Tech-Recipes. He is currently crafting iOS applications as a senior developer at Small Planet Digital in Brooklyn, New York.
View more articles by Quinn McHenry

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