Informix News
18 Nov 13 - ZDNet - Top 20 mobile skills in demand... Read
09 Sep 13 - telecompaper - Shaspa and Tatung have shown a new smart home platform at Ifa in Berlin. Powered by the IBM Informix software... Read
06 Sep 13 - IBM data magazine - Mission Accomplished - Miami, Florida will be the backdrop for the 2014 IIUG Informix Conference... Read
01 Feb 13 - IBM Data Magazine - Are your database backups safe? Lester Knutsen (IBM Champion) writes about database back up safety using "archecker"... Read
14 Nov 12 - IBM - IBM's Big Data For Smart Grid Goes Live In Texas... Read
3 Oct 12 - The Financial - IBM and TransWorks Collaborate to Help Louisiana-Pacific Corporation Achieve Supply Chain Efficiency... Read
28 Aug 12 - techCLOUD9 - Splunk kicks up a SaaS Storm... Read
10 Aug 12 - businessCLOUD9 - Is this the other half of Cloud monitoring?... Read
3 Aug 12 - IBM data management - Supercharging the data warehouse while keeping costs down IBM Informix Warehouse Accelerator (IWA) delivers superior performance for in-memory analytics processing... Read
2 Aug 12 - channelbiz - Oninit Group launches Pay Per Pulse cloud-based service... Read
28 May 12 - Bloor - David Norfolk on the recent Informix benchmark "pretty impressive results"... Read
23 May 12 - DBTA - Informix Genero: A Way to Modernize Informix 4GL Applications... Read
9 Apr 12 - Mastering Data Management - Upping the Informix Ante: Advanced Data Tools... Read
22 Mar 12 - developerWorks - Optimizing Informix database access... Read
14 Mar 12 - - International Informix User Group set to meet in San Diego... Read
1 Mar 12 - IBM Data Management - IIUG Heads West for 2012 - Get ready for sun and sand in San Diego... Read
1 Mar 12 - IBM Data Management - Running Informix on Solid-State Drives.Speed Up Database Access... Read
26 Feb 12 - - Better results, lower cost for a broad set of new IBM clients and partners... Read
24 Feb 12 - developerWorks - Informix Warehouse Accelerator: Continuous Acceleration during Data Refresh... Read
6 Feb 12 - PRLOG - Informix port delivers unlimited database scalability for popular SaaS application ... Read
2 Feb 12 - developerWorks - Loading data with the IBM Informix TimeSeries Plug-in for Data Studio... Read
1 Feb 12 - developerWorks - 100 Tech Tips, #47: Log-in to Fix Central... Read
13 Jan 12 - MC Press online - Informix Dynamic Server Entices New Users with Free Production Edition ... Read
11 Jan 12 - Computerworld - Ecologic Analytics and Landis+Gyr -- Suitors Decide to Tie the Knot... Read
9 Jan 12 - - DNS impact on Informix / Impacto do DNS no Informix... Read
8 Sep 11 - - IBM Offers Database Solution to Enable Smart Meter Data Capture... Read
1 Aug 11 - IBM Data Management Magazine - IIUG user view: Happy 10th anniversary to IBM and Informix... Read
8 Jul 11 - Database Trends and Applications - Managing Time Series Data with Informix... Read
31 May 11 - Smart Grid - The meter data management pitfall utilities are overlooking... Read
27 May 11 - IBM Data Management Magazine - IIUG user view: Big data, big time ( Series data, warehouse acceleration, and 4GLs )... Read
16 May 11 - Business Wire - HiT Software Announces DBMoto for Enterprise Integration, Adds Informix. Log-based Change Data Capture... Read
21 Mar 11 - Yahoo! Finance - IBM and Cable&Wireless Worldwide Announce UK Smart Energy Cloud... Read
14 Mar 11 - MarketWatch - Fuzzy Logix and IBM Unveil In-Database Analytics for IBM Informix... Read
11 Mar 11 - InvestorPlace - It's Time to Give IBM Props: How many tech stocks are up 53% since the dot-com boom?... Read
9 Mar 11 - DBTA - Database Administration and the Goal of Diminishing Downtime... Read
2 Feb 11 - DBTAs - Informix 11.7 Flexible Grid Provides a Different Way of Looking at Database Servers... Read
27 Jan 11 - exactsolutions - Exact to Add Informix Support to Database Replay, SQL Monitoring Solutions... Read
25 Jan 11 - PR Newswire - Bank of China in the UK Works With IBM to Become a Smarter, Greener Bank... Read
12 Oct 10 - Database Trends and Applications - Informix 11.7: The Beginning of the Next Decade of IBM Informix... Read
20 Sep 10 - - ITG analyst paper: Cost/Benefit case for IBM Informix as compared to Microsoft SQL Server... Read
20 Jul 10 - IBM Announcements - IBM Informix Choice Edition V11.50 helps deploy low-cost scalable and reliable solutions for Apple Macintosh and Microsoft Windows... Read
20 Jul 10 - IBM Announcements - Software withdrawal: Elite Support for Informix Ultimate-C Edition... Read
24 May 10 - eWeek Europe - IBM Supplies Database Tech For EU Smart Grid... Read
23 May 10 - SiliconIndia - IBM's smart metering system allows wise use of energy... Read
21 May 10 - CNET - IBM to help people monitor energy use... Read
20 May 10 - ebiz - IBM Teams With Hildebrand To Bring Smart Metering To Homes Across Britain... Read
19 May 10 - The New Blog Times - Misurare il consumo energetico: DEHEMS è pronto... Read
19 May 10 - ZDNet - IBM software in your home? Pact enables five-city smart meter pilot in Europe... Read
17 March 10 - ZDNet (blog) David Morgenstern - TCO: New research finds Macs in the enterprise easier, cheaper to manage than... Read
17 March 2010 - Virtualization Review - ...key components of Big Blue's platform to the commercial cloud such as its WebSphere suite of application ser vers and its DB2 and Informix databases... Read
10 February 2010 - The Wall Street Journal - International Business Machines is expanding an initiative to win over students and professors on its products. How do they lure the college crowd?... Read

End of Support Dates

IIUG on Facebook IIUG on Twitter

[ View Thread ] [ Post Response ] [ Return to Index ] [ Read Prev Msg ] [ Read Next Msg ]

IDS Forum

Re: subtract datetime value from null

Posted By: Jonathan Leffler
Date: Friday, 31 August 2012, at 10:30 a.m.

In Response To: subtract datetime value from null (PRAJAKTA CHIKHALE)

On Fri, Aug 31, 2012 at 6:05 AM, PRAJAKTA CHIKHALE <
> wrote:

> Hello I have a table in which there are two fields actual_time_from,
> actual_time_to. It stores sign on and sign off details. Null is inserted if
> actual time to extends past 23:59.
> How do I find hours worked if actual time to is null.
> I need to do something like
> select actual_time_to - actual_time_from as work_hours from t1;
> If I try using nvl(actual_time_to, to_date('24:00', '%H:%M')) it gives
> error
> -1263 A field in a datetime or interval is out of range, incorrect, or
> missing.
> If I try using nvl(actual_time_to, to_date('01 00:00', '%d %H:%M')) for
> fields
> where it is not null; 31 is put in day field. This leads to incorrect
> subtraction when actual_time_from is not null and actual_time_to is null.
> -30 06:00 is the output in such case when instead I want it to output 18:00
> when actual_time_from is "06:00" and actual_time_to is null.
> If I put nvl(actual_time_to, to_date('24:00', '%H:%M')), difference
> evaluates
> to 17:59 in previous case which is not correct logically.
> Things work only if both are null. But in that case, I can leave it blank.

Typo for 'if both are not null'?

> I can do the calculation by taking it in java but for 1 specific report I
> need
> to happen through sql may be through temporary tables but using sql only.

With addendum:

Sorry the line with output calculated as 17:59 should have read
> nvl(actual_time_to, to_date('23:59', '%H:%M'))

It may not be obvious (it probably isn't obvious), but it is often easiest
to do time calculations when the type is INTERVAL rather than DATETIME HOUR

In this case, I'd probably look to convert the times by subtracting
DATETIME(00:00) HOUR TO MINUTE from the times you've got stored. Note, in
particular, that INTERVAL(24:00) HOUR TO MINUTE is a very respectable value.

To calculate the end time:

NVL(actual_time_to - DATETIME(00:00) HOUR TO MINUTE, INTERVAL(24:00) HOUR

To calculate the start time:

(actual_time_from - DATETIME(00:00) HOUR TO MINUTE)

So the time taken is:

NVL(actual_time_to - DATETIME(00:00) HOUR TO MINUTE, INTERVAL(24:00) HOUR
(actual_time_from - DATETIME(00:00) HOUR TO MINUTE)

Which is a mouthful, but effective. Test case:



INSERT INTO WorkTimes VALUES('09:00', '17:00');
INSERT INTO WorkTimes VALUES('13:00', NULL);
SELECT Actual_time_to, actual_time_from,

(actual_time_from - DATETIME(00:00) HOUR TO MINUTE) fr_interval,

NVL(actual_time_to - DATETIME(00:00) HOUR TO MINUTE,
INTERVAL(24:00) HOUR TO MINUTE) AS to_interval,

NVL(actual_time_to - DATETIME(00:00) HOUR TO MINUTE,

(actual_time_from - DATETIME(00:00) HOUR TO MINUTE) AS time_worked
FROM WorkTimes
ORDER BY actual_time_from;

17:00 09:00 9:00 17:00 8:00

13:00 13:00 24:00 11:00

The output looks better in fixed-width font, of course.

Jonathan Leffler <> #include <disclaimer.h>
Guardian of DBD::Informix - v2011.0612 -
"Blessed are we who can laugh at ourselves, for we shall never cease to be


Messages In This Thread

[ View Thread ] [ Post Response ] [ Return to Index ] [ Read Prev Msg ] [ Read Next Msg ]

IDS Forum is maintained by Administrator with WebBBS 5.12.