Postgres Pro
Downloads
Home   >   mailing lists

Thread: adding time to a datetime field ... how?

adding time to a datetime field ... how?

From
The Hermit Hacker
Date:
I hate coming up with subjects...

I have a table with two fields: start_time::datetime and
acctsessiontime::int4...I want to add the second to the first, to give me
a stop_time...

if I do:

select start_time,start_time+acctsessiontime from log;

I get a stop_time 'acctsessiontime' days after start_time, instead of
'acctsessiontime' seconds later...

Is there some way of telling it to pass seconds instead of days?

Thanks

Marc G. Fournier                   ICQ#7615664               IRC Nick: Scrappy
Systems Administrator @ hub.org 
primary: scrappy@hub.org           secondary: scrappy@{freebsd|postgresql}.org

Re: [SQL] adding time to a datetime field ... how?

From
Margarit Nickolov
Date:
select start_time,start_time+acctsessiontime::timespan from log;

On Wed, 15 Dec 1999, The Hermit Hacker wrote:

> 
> I hate coming up with subjects...
> 
> I have a table with two fields: start_time::datetime and
> acctsessiontime::int4...I want to add the second to the first, to give me
> a stop_time...
> 
> if I do:
> 
> select start_time,start_time+acctsessiontime from log;
> 
> I get a stop_time 'acctsessiontime' days after start_time, instead of
> 'acctsessiontime' seconds later...
> 
> Is there some way of telling it to pass seconds instead of days?
> 
> Thanks
> 
> Marc G. Fournier                   ICQ#7615664               IRC Nick: Scrappy
> Systems Administrator @ hub.org 
> primary: scrappy@hub.org           secondary: scrappy@{freebsd|postgresql}.org 
> 
> 
> ************
> 
>

Re: [SQL] adding time to a datetime field ... how?

From
Vladimir Terziev
Date:
  Try
  select start_time,          abstime_datetime(start_time::abstime + acctsessiontime)      from log;

  Regards!
Vladimir

Re: [SQL] adding time to a datetime field ... how?

From
Peter Eisentraut
Date:
On 1999-12-15, Margarit Nickolov mentioned:

> select start_time,start_time+acctsessiontime::timespan from log;

Wow, that is really weird. I would consider it confusing behaviour at
best if an explicit cast interprets an int as seconds whereas an implicit
conversion thinks it's days.


-- 
Peter Eisentraut                  Sernanders väg 10:115
peter_e@gmx.net                   75262 Uppsala
http://yi.org/peter-e/            Sweden

Re: [SQL] adding time to a datetime field ... how?

From
Margarit Nickolov
Date:
 timespan type is `` time interval '@ <number> <units>' '' (try: db=>\dT),
 and you can convert int4 to any timespan units this way:
 textcat(int4_field, ' units_you_like')::timespan

units can be: secs, mins, hours, days, months, years 

Margarit.


On Fri, 17 Dec 1999, Peter Eisentraut wrote:

> On 1999-12-15, Margarit Nickolov mentioned:
> 
> > select start_time,start_time+acctsessiontime::timespan from log;
> 
> Wow, that is really weird. I would consider it confusing behaviour at
> best if an explicit cast interprets an int as seconds whereas an implicit
> conversion thinks it's days.
> 
> 
> -- 
> Peter Eisentraut                  Sernanders v�g 10:115
> peter_e@gmx.net                   75262 Uppsala
> http://yi.org/peter-e/            Sweden
> 
> 
>