Re: Help On Postgresql

On Thu, 23 Aug 2001, Jaydip wrote:

> a) How do I retrieve the Year,Month,Day,Hr,Minute or Second value from a Date/DateTime variable.
> 
>     For Example : i> In Oracle to_char(dt,'yyyy') - for extracting the year value from a date variable dt
>                  ii> In SqlServer datepart(hh,dt) - for extracting the Hour value from a date variable dt

I'm not sure what versions all of these came in at, but:There is a to_char which should be somewhat compatible with oracle's,as well as a datepart (whose part names are like 'year', 'month', ...)and extract( from dt)

> b) Can I create an identity column in Postgresql the value of which column will start from 1 say and keep
>     on incrementing by 1 OR how can I serve my purpose in any other way.

Look at sequences and the serial pseudo-type.