Solved

how to write logic in trigger if(TOTAL_LARGE > CURRENT_LARGE) then rollback the transaction.

Posted on 2013-11-12
1
307 Views
Last Modified: 2013-11-17
CREATE TRIGGER [dbo].[EMPJOBS_Trigger] ON [EMPjobs]
FOR INSERT
AS
BEGIN

select location_jobs.id as job_id
      ,     location_jobs.pool_large as TOTAL_LARGE
      ,     sum( case when ( job.job_type='LARGE' and job.job_status='NEW') then 1 else 0 end) as CURRENT_LARGE
    from locations location_jobs    
         LEFT OUTER JOIN emp_jobs job  on location_jobs.id=job.storage_id
              and job.storage_id=(SELECT  storageid  from INSERTED) and job.job_type in ('LARGE')
              and job.job_status='NEW'
    where location_jobs.id=(SELECT  storageid  from INSERTED)
    group by location_jobs.id, location_jobs.pool_large
      
      how to write logic in trigger if(TOTAL_LARGE > CURRENT_LARGE) then rollback the transaction.
      
      if(TOTAL_LARGE > CURRENT_LARGE)
  BEGIN
    PRINT 'exceeded the limit.'
    RAISERROR ('exceeded the limit. ')
    ROLLBACK TRANSACTION
    RETURN
  END
 
  END
  GO
0
Comment
Question by:chaitu chaitu
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
1 Comment
 
LVL 15

Accepted Solution

by:
dbbishop earned 500 total points
ID: 39646273
Will EMPjobs ever have more than one row inserted at a time? Before you answer, think of all scenarios where it could, a batch process, maintenance, etc. If it can, you cannot use the logic flow you have above.
"job.storage_id=(SELECT  storageid  from INSERTED)" must return one, and only one row. Same with the subsequent WHERE clause. If more than one row exists in inserted, an error will be generated.

All that aside, assuming only one row will ever be inserted at a time, try something like this:
CREATE TRIGGER [dbo].[EMPJOBS_Trigger] ON [EMPjobs]
	FOR INSERT
AS
	BEGIN

		DECLARE	@TotalLarge INT
		DECLARE	@CurrentLarge INT 

		SELECT	@TotalLarge = location_jobs.pool_large,
				@CurrentLarge = SUM(CASE WHEN job.job_type = 'LARGE'
											  AND job.job_status = 'NEW'
										 THEN 1
										 ELSE 0
									END)
		FROM	locations.location_jobs
		LEFT OUTER JOIN emp_jobs job
		ON		location_jobs.id = job.storage_id
				AND job.storage_id = ( SELECT storageid FROM INSERTED )
				AND job.job_type IN ( 'LARGE' )
				AND job.job_status = 'NEW'
		WHERE	location_jobs.id = ( SELECT storageid FROM INSERTED )
		GROUP BY location_jobs.id,
				location_jobs.pool_large
      
--      how to write logic in trigger if(TOTAL_LARGE > CURRENT_LARGE) then rollback the transaction.
      
		IF @TotalLarge > @CurrentLarge 
			BEGIN
				RAISERROR ('Exceeded the limit.', 0, 1)
				ROLLBACK TRANSACTION
				RETURN
			END
  
	END
  GO 

Open in new window

0

Featured Post

Will your db performance match your db growth?

In Percona’s white paper “Performance at Scale: Keeping Your Database on Its Toes,” we take a high-level approach to what you need to think about when planning for database scalability.

Question has a verified solution.

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

This post looks at MongoDB and MySQL, and covers high-level MongoDB strengths, weaknesses, features, and uses from the perspective of an SQL user.
In part one, we reviewed the prerequisites required for installing SQL Server vNext. In this part we will explore how to install Microsoft's SQL Server on Ubuntu 16.04.
In this video, viewers will be given step by step instructions on adjusting mouse, pointer and cursor visibility in Microsoft Windows 10. The video seeks to educate those who are struggling with the new Windows 10 Graphical User Interface. Change Cu…
Add bar graphs to Access queries using Unicode block characters. Graphs appear on every record in the color you want. Give life to numbers. Hopes this gives you ideas on visualizing your data in new ways ~ Create a calculated field in a query: …

632 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