Join IIUG
 for   
 

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 - BernieSpang.com - 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 - BernieSpan.com - 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 - planetIDS.com - DNS impact on Informix / Impacto do DNS no Informix... Read
8 Sep 11 - TMCnet.com - 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 - planetIDS.com - 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: NULL situation

Posted By: Jarrod Teale
Date: Monday, 8 February 2010, at 4:52 p.m.

In Response To: NULL situation (John Adamski)

The second command will fail - you can't add a not null clause to a
column that contains NULLs.

The first one may work - depends on how the NULL gets into the column.
If the application is saying "INSERT INTO (fullname) VALUES (NULL)" then
the default won't help - it will take the NULL and store it.
If the application is simply omitting the column from the insert /
update, then the default clause will apply

Take the test script below:

create table testnulls (

rownum serial,

fullname char(32)

);

insert into testnulls values (0, "Jarrod");
insert into testnulls values (0, "Jarrod2");
insert into testnulls values (0, NULL);
insert into testnulls values (0, NULL);
insert into testnulls values (0, "Jarrod3");

-- Add Default clause
alter table testnulls modify fullname char(32) default '';
select rownum, "STUFF" || NVL(TRIM(fullname), "-NULLHERE-") || "STUFF"
from testnulls;

-- Explicitly add NULL
insert into testnulls values (0, NULL);
select rownum, "STUFF" || NVL(TRIM(fullname), "-NULLHERE-") || "STUFF"
from testnulls;

-- Add row with no defined name
insert into testnulls (rownum) values (0);
select rownum, "STUFF" || NVL(TRIM(fullname), "-NULLHERE-") || "STUFF"
from testnulls;

-- Try to add the not null clause - fails.
alter table testnulls modify fullname char(32) default '' NOT NULL;
select rownum, "STUFF" || NVL(TRIM(fullname), "-NULLHERE-") || "STUFF"
from testnulls;

AND THE OUTPUT below here

[informix@jarrod(10.10.70.133) ~]$ dbaccess jarrod test.sql

Database selected.

Table created.

1 row(s) inserted.

1 row(s) inserted.

1 row(s) inserted.

1 row(s) inserted.

1 row(s) inserted.

Table altered.

rownum (expression)

1 STUFFJarrodSTUFF

2 STUFFJarrod2STUFF

3 STUFF-NULLHERE-STUFF

4 STUFF-NULLHERE-STUFF

5 STUFFJarrod3STUFF

5 row(s) retrieved.

1 row(s) inserted.

rownum (expression)

1 STUFFJarrodSTUFF

2 STUFFJarrod2STUFF

3 STUFF-NULLHERE-STUFF

4 STUFF-NULLHERE-STUFF

5 STUFFJarrod3STUFF

6 STUFF-NULLHERE-STUFF

6 row(s) retrieved.

1 row(s) inserted.

rownum (expression)

1 STUFFJarrodSTUFF

2 STUFFJarrod2STUFF

3 STUFF-NULLHERE-STUFF

4 STUFF-NULLHERE-STUFF

5 STUFFJarrod3STUFF

6 STUFF-NULLHERE-STUFF

7 STUFFSTUFF

7 row(s) retrieved.

530: Check constraint () failed.
Error in line 25
Near character position 1

rownum (expression)

1 STUFFJarrodSTUFF

2 STUFFJarrod2STUFF

3 STUFF-NULLHERE-STUFF

4 STUFF-NULLHERE-STUFF

5 STUFFJarrod3STUFF

6 STUFF-NULLHERE-STUFF

7 STUFFSTUFF

7 row(s) retrieved.

Database closed.

Jarrod Teale
Team Lead - Manufacturing Execution Systems
Automation & Process Control Group
NZ Technical
Fonterra
email: jarrod.teale@fonterra.com

-----Original Message-----
From: ids-bounces@iiug.org [mailto:ids-bounces@iiug.org] On Behalf Of
John Adamski
Sent: Tuesday, 9 February 2010 10:31 a.m.
To: ids@iiug.org
Subject: NULL situation [18944]

HPUX 11.23 IDS 10.00.FC9

We are trying to find the best solution for a situation that our
third-party software and their database design has created. Since we do
not have full control of the third-party software nor their database
design we need a way to clean up the mess left behind.

The situation is this: we get null values where the software is not
expecting nulls or is not coded to handle nulls might be more accurate.
Most of the null values come for the software itself. Example might be
program A creates a row in an accounting table and program Q down the
road then tries to do something with that row after a number of other
programs have manipulated the data, but it fails cause a field has a
null. Or worse yet is processes the row incorrectly because it did not
have coding to handle nulls.

Since we have a bit more flexibility in changing the tables in the
system rather than the actual software, the tentative plan is to modify
the tables to have default values on the fields we know causes us
problems.

A question came up that I can't remember back to my training 8 years ago
so want to pose it here. If we add a default to a field already in the
table will it apply that default to null records or will it just apply
the default to new records? My memory say as long as not null clause is
not added it will leave current rows alone.

Example if we have a NAMES table that has a field called fullname that
is a
char(32) with no default set an also doesn't have the not null clause -
just a plain char(32). And now I alter the table to have a default of
blank (''), my assumption is since null are still allowed it would leave
the nulls already in the table alone. I would have to add the not null
clause, which seems like a catch 22 as wouldn't I get an error cause I
have nulls? I need a memory refresh.

alter table modify fullname char(32) default ''; -- only new rows get a
blank value ?

alter table modify fullname char(32) default '', not null; -- will this
change nulls already in table or cause an error?

John

************************************************************************
*******
Forum Note: Use "Reply" to post a response in the discussion forum.

DISCLAIMER:
This email contains confidential information and may be legally privileged. If you are not the intended recipient or have received this email in error, please notify the sender immediately and destroy this email.
You may not use, disclose or copy this email or its attachments in any way.
Any opinions expressed in this email are those of the author and are not necessarily those of the Fonterra Co-operative Group.
http://www.fonterra.com/

Messages In This Thread

  • NULL situation
    John Adamski -- Monday, 8 February 2010, at 4:30 p.m.
    • RE: NULL situation
      Jarrod Teale -- Monday, 8 February 2010, at 4:52 p.m.
    • Re: NULL situation
      Art Kagel -- Monday, 8 February 2010, at 6:21 p.m.

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

IDS Forum is maintained by Administrator with WebBBS 5.12.