Solved

Writing Triggers to maintain data integrity

Posted on 2013-05-10
2
193 Views
Last Modified: 2013-05-13
I have an Access 2003 application with SQL Server 2012 linked tables.

The "Locations" table has four fields of concern, namely ParentId, WIP, Reserved, OwnedByParent

WIP, Reserved, and OwnedByParent are smallint datatype, can only be either -1 or 0 per a check constraint, and can not be Null.  ParentId can be Null and is an int datatype.

The Requirement: Whenever there is a record with a value for ParentId (i.e. ParentId is not Null) and WIP=0, there needs to also be one and only one record with WIP = -1 and the same values for ParentId, Reserved, and OwnedByParent as that record.

I think this can be accomplished by:
1.) Creating a trigger such that whenever a record with a value for ParentId is inserted, a record is also inserted with WIP = -1 and the same ParentId, Reserved, and OwnedByParent values as the record being inserted if a record meeting that criteria doesn't already exist, and
2.) Create another trigger that rolls back a transaction if a record being inserted has WIP = -1 and there already exists a record with WIP = -1 and with the same ParentId, Reserved, and OwnedByParent values as the record being inserted.

Is there an easier way to accomplish the requirement?  If not how can I write the triggers to do this?  I prefer not to put this code in the front end application because I'd have to include code in any part of the application that is used to maintain data in the locations table, however that is an option if it is too complicated to do with triggers in SQL Server.
0
Comment
Question by:Declan_Basile
2 Comments
 
LVL 23

Accepted Solution

by:
Ioannis Paraskevopoulos earned 500 total points
ID: 39157655
Hi,

I would suggest calling a Stored Procedure for both functions instead of a triger. So you will probably have to change your app to use the sp instead of a standard Insert, but you may have more manageability this way.
I am not really font of triggers.

Let me know if you would like some sample code.

Giannis
0
 
LVL 1

Author Closing Comment

by:Declan_Basile
ID: 39162589
Thanks
0

Featured Post

U.S. Department of Agriculture and Acronis Access

With the new era of mobile computing, smartphones and tablets, wireless communications and cloud services, the USDA sought to take advantage of a mobilized workforce and the blurring lines between personal and corporate computing resources.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

A simple tool to export all objects of two Access files as text and compare it with Meld, a free diff tool.
For both online and offline retail, the cross-channel business is the most recent pattern in the B2C trade space.
In Microsoft Access, learn how to “cascade” or have the displayed data of one combo control depend upon what’s entered in another. Base the dependent combo on a query for its row source: Add a reference to the first combo on the form as criteria i…
Viewers will learn how to use the SELECT statement in SQL to return specific rows and columns, with various degrees of sorting and limits in place.

863 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question

Need Help in Real-Time?

Connect with top rated Experts

23 Experts available now in Live!

Get 1:1 Help Now