Overriding System Messages

Question

Overriding System Messages

johncyriac

SSCommitted

Points: 1542
More actions
October 14, 2003 at 8:27 am

#160823

Overriding System Messages
All we know the introduction of constraints was a great enhancement to RDBM’S. Look but when you try to violate a constraint, System generates an error message which tells about all most all the stuff but of a little relevance for the end user.
Now let’s have a discussion on
Overriding System Messages
Let me tell my idea In my employees table I am having a Grade filed which references an empgrade table, On the violation of this constraint I wish to get the following error message “Grade field expects a valid grade ” or something like that
Pl contribute

Viewing 5 posts - 1 through 4 (of 4 total)

You must be logged in to reply to this topic. Login to reply

K. Brian Kelley SSC Guru Points: 114642 More actions · Answer 1

You won't be able to override the error message directly. What you can do is trap for an error condition before hand. For instance (within a stored procedure):



IF NOT EXISTS (SELECT grade FROM dbo.ValidGrades WHERE grade = @grade)

BEGIN

  RAISERROR('Grade field expects a valid grade.', 14, 1)

  RETURN(1)

END

K. Brian Kelley

http://www.truthsolutions.com/

Author: Start to Finish Guide to SQL Server Performance Monitoring

http://www.netimpress.com/

Edited by - bkelley on 10/14/2003 12:06:56 PM

K. Brian Kelley
@kbriankelley

johncyriac SSCommitted Points: 1542 More actions · Answer 2

In that case the very purpose of constraints itself is questioned, each time you have to see in the lookup table means even you can avoid the constraint as a whole. I too know at present the RDBMS’ are not supporting this feature. But I wish to have a discussion on custom messages as part of Constraints or overriding the System Messages.

Frends come forward with new Syntax and Ideas on this Topic

jcool SSC Eights! Points: 863 More actions · Answer 3

Here's what I do. I give the constraint a meaningful name, like in your case:

CK_grade_[Grade_field_expects_a_valid_grade].

The user will get a check constraint violation message and also the constraint name, which gives some explanation. Other than that there's nothing more you can do with check constraints in the database.

noeld SSC Guru Points: 96590 More actions · Answer 4

The solution to this problem is to handle the error message on the CLIENT side. In other words use structured exception handling, trap the exception and translate the message to a user friendly format.

HTH

* Noel