[Year 12 IT Apps] IARTV October test

[Lumsden, Richard G]

See attch



-----Original Message-----
From: itapps-bounces at edulists.com.au
[mailto:itapps-bounces at edulists.com.au] On Behalf Of Mark Kelly
Sent: Thursday, 3 September 2009 3:22 PM
To: Year 12 IT Applications Teachers' Mailing List
Subject: Re: [Year 12 IT Apps] IARTV October test

Oops.  Hit SEND too soon.  The second last para should read:

e.g. a person can only be allocated to a location that exists in the
location table.  This can be done by forcing employees' locations be
selected from a drop-down list whose contents are populated
automatically with values from the locations list.  You can also set up
a validation rule stating that the value in the location field must 
exist in a limited list.


Mark Kelly wrote:
> Hi all.
> 
> Anyone else using the CSE's IARTV October test for ITA?
> 
> I'm having issues with one of its database questions (4c):
> 
> "A one-to-many relationship is established between the Employees Table

> and the Locations table.
> 
> Explain why setting this relationship would prevent a row in the 
> location table being deleted if some employees were still allocated to

> that location."
> 
> The suggested answer is "Setting a relationship will prevent deletion
of 
> any row that is used as a key in an existing relationship -
referential 
> integrity."
> 
> This is just not true, at least in Filemaker.  You certainly can
delete 
> a record in a related table when local records still reference it. Do 
> other databases behave differently?
> 
> Secondly, as I understand it, referential integrity (at least in 
> Filemaker) is not automatically created when a relationship is set up.

> It's a deliberate strategy to ensure that values can only selected
from 
> an existing list of options.
> 
> e.g. a person can only be allocated to a location that exists in the 
> location table.  This can be done by forcing employees' locations be 
> selected from a drop-down list whose contents are populated 
> automatically with values from the locations list.  You can also set
up 
> a validation rule stating that the value in the location
> 
> Again, do other databases have referential integrity enforced by the 
> RDBMS - and how do they do it?
> 


-- 
Mark Kelly
Manager - Information Systems
McKinnon Secondary College
McKinnon Rd McKinnon 3204, Victoria, Australia
Direct line / Voicemail: 8520 9085
School Phone +613 8520 9000
School Fax +613 9578 9253
kel at mckinnonsc.vic.edu.au

Webmaster - http://www.mckinnonsc.vic.edu.au
IT Lecture notes: http://vceit.com
Moderator: IT Applications Mailing List

RealMenDon'tNeedSpacebars.

_______________________________________________
http://www.edulists.com.au - FAQ, resources, subscribe, unsubscribe
IT Applications Mailing List kindly supported by
http://www.vcaa.vic.edu.au/vce/studies/infotech/itapplications3-4.html -
Victorian Curriculum and Assessment Authority and
http://www.vitta.org.au  - VITTA Victorian Information Technology
Teachers Association Inc

Important - This email and any attachments may be confidential. If received in error, please contact us and delete all copies. Before opening or using attachments check them for viruses and defects. Regardless of any loss, damage or consequence, whether caused by the negligence of the sender or not, resulting directly or indirectly from the use of any attached files our liability is limited to resupplying any affected attachments. Any representations or opinions expressed are those of the individual sender, and not necessarily those of the Department of Education and Early Childhood Development.
-------------- next part --------------
A non-text attachment was scrubbed...
Name: Access example.doc
Type: application/msword
Size: 97280 bytes
Desc: Access example.doc
Url : http://www.edulists.com.au/pipermail/itapps/attachments/20090903/f4fcd4cc/Accessexample-0001.doc