Google Groups no longer supports new Usenet posts or subscriptions. Historical content remains viewable.
Dismiss
[SQL] generated dates from record dates - suggestions
0 views
Skip to first unread message
Gary Stainburn
Aug 20, 2012, 8:17:46 AM8/20/12
to
Hi folks.
I've got a table with three dates which are populated from an external source.
I then want to have a view with two calculated dates in it, e.g.
if date_1 is null and date_2 is null then date_a=NULL
if date_1 is not null and date 2 is null then date_a=date_1+'90 days'
if date_1 > date3 rhen date_b=date1 else date_b=date2
etc.
What's the best way to do this?
I know it's a quite open question but I'm interested to hear different
responses
--
Gary Stainburn
Group I.T. Manager
Ringways Garages
http://www.ringways.co.uk
--
Sent via pgsql-sql mailing list (pgsq...@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-sql
I've got a table with three dates which are populated from an external source.
I then want to have a view with two calculated dates in it, e.g.
if date_1 is null and date_2 is null then date_a=NULL
if date_1 is not null and date 2 is null then date_a=date_1+'90 days'
if date_1 > date3 rhen date_b=date1 else date_b=date2
etc.
What's the best way to do this?
I know it's a quite open question but I'm interested to hear different
responses
--
Gary Stainburn
Group I.T. Manager
Ringways Garages
http://www.ringways.co.uk
--
Sent via pgsql-sql mailing list (pgsq...@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-sql
Oliveiros d'Azevedo Cristina
Aug 20, 2012, 10:19:58 AM8/20/12
to
With a CASE ... WHEN statement?
Best,
Oliver
Best,
Oliver
Gary Stainburn
Aug 21, 2012, 6:31:49 AM8/21/12
to
On Tuesday 21 August 2012 02:01:55 Johnny Winn wrote:
> I would define a function and use it to abstract the expected behavior. It
> would appear that there are several conditions so this abstraction would
> provide for both usability and maintainability.
>
> - Johnny
Johnny,
This was what I was wondering, and was looking for suggestions / best
practices on how to do this.
I had first thought of embedding case/when statements in the view but it could
easily become unweildy
> I would define a function and use it to abstract the expected behavior. It
> would appear that there are several conditions so this abstraction would
> provide for both usability and maintainability.
>
> - Johnny
Johnny,
This was what I was wondering, and was looking for suggestions / best
practices on how to do this.
I had first thought of embedding case/when statements in the view but it could
easily become unweildy
Jasen Betts
Aug 21, 2012, 7:14:53 AM8/21/12
to
On 2012-08-20, Gary Stainburn <gary.st...@ringways.co.uk> wrote:
> Hi folks.
>
> I've got a table with three dates which are populated from an external source.
> I then want to have a view with two calculated dates in it, e.g.
>
> if date_1 is null and date_2 is null then date_a=NULL
> if date_1 is not null and date 2 is null then date_a=date_1+'90 days'
> if date_1 > date3 rhen date_b=date1 else date_b=date2
> etc.
>
> What's the best way to do this?
CASE looks good.
> Hi folks.
>
> I've got a table with three dates which are populated from an external source.
> I then want to have a view with two calculated dates in it, e.g.
>
> if date_1 is null and date_2 is null then date_a=NULL
> if date_1 is not null and date 2 is null then date_a=date_1+'90 days'
> if date_1 > date3 rhen date_b=date1 else date_b=date2
> etc.
>
> What's the best way to do this?
> I know it's a quite open question but I'm interested to hear different
> responses
it?
--
⚂⚃ 100% natural
Gary Stainburn
Aug 21, 2012, 8:15:58 AM8/21/12
to
On Tuesday 21 August 2012 12:14:53 Jasen Betts wrote:
> > What's the best way to do this?
>
> CASE looks good.
>
> > I know it's a quite open question but I'm interested to hear different
> > responses
>
> "date_b" on line three, is that a typo? if not how am i to interpret
> it?
The table contains date_1, date_2 and date_3. The resulting view needs to
> > What's the best way to do this?
>
> CASE looks good.
>
> > I know it's a quite open question but I'm interested to hear different
> > responses
>
> "date_b" on line three, is that a typo? if not how am i to interpret
> it?
contain date_1, date_2, date_3, date_a and date_b where date_a and date_b are
calculated based on the first three (plus a text field).
Gary Stainburn
Aug 22, 2012, 6:49:53 AM8/22/12
to
On Tuesday 21 August 2012 13:11:06 Johnny Winn wrote:
> CREATE OR REPLACE FUNCTION get_dates(date, date, date) RETURNS TABLE(date1
> date, date2 date)
> AS $$
> DECLARE
> date_1 DATE := NULL;
> date_2 DATE := NULL;
> BEGIN
>
> -- test your conditions here
>
> RETURN QUERY SELECT date_1::date, date_2::date;
> END;
> $$
> LANGUAGE PLPGSQL;
>
> I hope this helps,
> Johnny
Johnny,
Having gone down the CASE/WHEN route and found it too clumsy I'm now looking
at using this method. I'm just about to start writing the function, but I'm
wondering how I would include this is the select / view .
Gary
> CREATE OR REPLACE FUNCTION get_dates(date, date, date) RETURNS TABLE(date1
> date, date2 date)
> AS $$
> DECLARE
> date_1 DATE := NULL;
> date_2 DATE := NULL;
> BEGIN
>
> -- test your conditions here
>
> RETURN QUERY SELECT date_1::date, date_2::date;
> END;
> $$
> LANGUAGE PLPGSQL;
>
> I hope this helps,
> Johnny
Johnny,
Having gone down the CASE/WHEN route and found it too clumsy I'm now looking
at using this method. I'm just about to start writing the function, but I'm
wondering how I would include this is the select / view .
Gary
0 new messages