Help: How to increment a data

[worth2talk]

Hi Gurus,

I am a newbie for MYSQL. The i want to know is as described below:

I have created a table say 'temperature' as below.

 

id | currentTemp  | MinTemp  | MaxTemp | Time

---|--------------|-----------|----------|----------

1  |      25        |    5        |    32      | 10:10 am

 

and so on...

 

Now suppose i want to increment 'currentTemp' field data by 1 at every 1 hour, then how to do it ?

One simple way is to read this row and then add 1 to 'currentTemp' field value and update the 'currentTemp' field.

 

Is there another way to achieve the same ??

 

Quick answer will be appreciated ..!!

[Wildbug]

You can use a user-defined variable:

 

SET @a:=0;UPDATE temperature SET currentTemp=currentTemp+(@a:=@a+1);

[artacus]

I'm assuming that you want to add a new row for each reading.

What you want is an auto-increment field for id.

 

http://dev.mysql.com/doc/refman/5.0/en/example-auto-increment.html

[bubblegum.anarchy]

a cronjob that runs the following query every hour

 

INSERT INTO temperature SELECT currentTemp + 1, MinTemp, MaxTemp, Time FROM temperature ORDER BY id DESC LIMIT 1;