Thread: How does operation with data types time???

Hello

I have another question, please should someone help me??

my question is :
How may does operation in fields of type "time"??
for example , i want does the following query:
lab=>update ctrl set curren_time = current_time - 3;

is tell o want subtract three minutes to values in field current_time that
is of tipe time,

Is posible this???

Please help me





Pablo Salazar LoaizaAsistente de Redes CESERCOMP-ESPOL

> I have another question, please should someone help me??

Sure. I understand this one, but didn't quite follow the previous
question. Sorry...

> How may does operation in fields of type "time"??
> for example , i want does the following query:
>  lab=>update ctrl set curren_time = current_time - 3;
> is tell o want subtract three minutes to values in field current_time that
> is of tipe time,

It looks to me that we are missing a math routine to make this
transparent (at least once you make the "3" into "timespan '3 min'").
But there is a workaround:

postgres=> select time(datetime('today', time '3:30') - timespan '3
min');
time    
--------
03:27:00
(1 row)

Hope this helps...
                       - Thomas

-- 
Thomas Lockhart                lockhart@alumni.caltech.edu
South Pasadena, California